Journal articles: 'Vector network analyzer (VNA)'

1

Anwar Zainuddin, Ahmad, Anis Nurashikin Nordin, Rosminazuin Ab. Rahim, Aliza Aini Md. Ralib, Sheroz Khan, Cyril Guines, Matthieu Chatras, and Arnaud Pothier. "Verification of Quartz Crystal Microbalance Array using Vector Network Analyzer and OpenQCM." Indonesian Journal of Electrical Engineering and Computer Science 10, no. 1 (April 1, 2018): 84. http://dx.doi.org/10.11591/ijeecs.v10.i1.pp84-93.

Full text

Abstract:

Quartz Crystal Microbalance (QCM) is a device that allows non-destructive measurements of r in situ reaction activities. In this article, an array comprising of six 3MHz QCM sensors in an array were characterized using a vector network analyzer and OpenQCM, a portable measuring instrument that measures change in resonance frequency. Measurements of S21 transmission characteristics using the vector network analyzer provides the resonance frequency and can also be used to derive the RLC equivalent electrical circuit values of a resonant two-port network based on the Butterworth-Van Dyke model. In this work, Rm, Lm, Cm and Co were obtained via curve-fitting of the measurement results to the simulated results. Measurements were done in triplicates to verify reproducibility for all 6 sensors. For comparison, measurements were also done using a portable, open-source instrument, OpenQCM. The OpenQCM instrument directly measures changes in resonance frequencies, making it ideal for biosensing experiments, which correlate changes in mass with changes in resonance frequencies. Comparison between resonance frequency measurements using VNA and OpenQCM exhibit low percentage difference 0.2%. This QCM sensor array has the potential of conducting real-time, point-of-care analyses for detection of biological molecules.

APA, Harvard, Vancouver, ISO, and other styles

2

Rolfes, I., B. Will, and B. Schiek. "Calibration-measurement unit for the automation of vector network analyzer measurements." Advances in Radio Science 6 (May 26, 2008): 27–30. http://dx.doi.org/10.5194/ars-6-27-2008.

Full text

Abstract:

Abstract. With the availability of multi-port vector network analyzers, the need for automated, calibrated measurement facilities increases. In this contribution, a calibration-measurement unit is presented which realizes a repeatable automated calibration of the measurement setup as well as a user-friendly measurement of the device under test (DUT). In difference to commercially available calibration units, which are connected to the ports of the vector network analyzer preceding a measurement and which are then removed so that the DUT can be connected, the presented calibration-measurement unit is permanently connected to the ports of the VNA for the calibration as well as for the measurement of the DUT. This helps to simplify the calibrated measurement of complex scattering parameters. Moreover, a full integration of the calibration unit into the analyzer setup becomes possible. The calibration-measurement unit is based on a multiport switch setup of e.g. electromechanical relays. Under the assumption of symmetry of a switch, on the one hand the unit realizes the connection of calibration standards like one-port reflection standards and two-port through connections between different ports and on the other hand it enables the connection of the DUT. The calibration-measurement unit is applicable for two-port VNAs as well as for multiport VNAs. For the calibration of the unit, methods with completely known calibration standards like SOLT (short, open, load, through) as well as self-calibration procedures like TMR or TLR can be applied.

APA, Harvard, Vancouver, ISO, and other styles

3

Anderson, Geoffrey. "Scanning Microwave Microscopy for Nanoscale Electrical Characterization." Microscopy Today 21, no. 6 (November 2013): 32–36. http://dx.doi.org/10.1017/s1551929513000965.

Full text

Abstract:

Recently, a highly sensitive imaging mode for, complex, calibrated electrical and spatial measurements was made available to atomic force microscope (AFM) users. Scanning microwave microscopy (SMM), an award-winning AFM mode of operation developed by Agilent Technologies, combines the comprehensive electrical measurement capabilities of a microwave vector network analyzer (VNA) with the nanoscale spatial resolution of an AFM.

APA, Harvard, Vancouver, ISO, and other styles

4

Das, Hangsa Raj, Rajesh Dey, and Sumanta Bhattacharya. "ANALYSIS OF MICRO-STRIP PATCH ANTENNA FOR WI-FI APPLICATIONS." Information Management and Computer Science 3, no. 2 (December 7, 2020): 25–26. http://dx.doi.org/10.26480/imcs.02.2020.25.26.

Full text

Abstract:

For the purposes of Wi-Fi applications, the objective of this Rectangular Micro-Strip Patch antenna design. The aim of this research paper is to design, simulate, test and analyses a new form of rectangular micro-stip patch antenna with both RT Duroid and two-feed line substrates. The proposed model consists of the Linear Polarization Moment Process. The latest concept analytical analysis is simulation using the HFSS tool and the ZNB20 vector network analyzer (VNA) is used for experimental validation.

APA, Harvard, Vancouver, ISO, and other styles

5

Wang, Li, and Bo Geng. "Preparation and Electromagnetic Properties of Ferriferrous Oxide/Polyaniline Composites." Applied Mechanics and Materials 633-634 (September 2014): 302–5. http://dx.doi.org/10.4028/www.scientific.net/amm.633-634.302.

Full text

Abstract:

By using chemical oxidative polymerization method, ferriferrous oxide/polyaniline (Fe3O4/PANI) composites are successfully synthesized. The composites are characterized by Fourier transform infrared spectra (FTIR), vibrating sample magnetometer (VSM), and vector network analyzer (VNA). With the amount of Fe3O4 increase, the saturation magnetization and remnant magnetization of Fe3O4/PANI composites decrease, while the coercivity remains unchanged. The addition of Fe3O4 makes the reflection loss (RL) of Fe3O4/PANI composites decreases and the microwave absorption increases.

APA, Harvard, Vancouver, ISO, and other styles

6

Abdullah, Bualkar, Sultan Ilyas, and Dahlang Tahir. "Nanocomposites Fe/Activated Carbon/PVA for Microwave Absorber: Synthesis and Characterization." Journal of Nanomaterials 2018 (July 8, 2018): 1–6. http://dx.doi.org/10.1155/2018/9823263.

Full text

Abstract:

Nanocomposites, activated carbon/polyvinyl alcohol (AC/PVA) filled with Fe to form Fe/AC/PVA, were characterized by using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and vector network analyzer (VNA). The crystal orientations from Fe are (104), (110), and (200) and the bonding formations of AC are O-H, C-H, and C=C show existence in nanocomposites, which may be due to the Fe that has been filled the pore of AC via a chemical bond. 20% AC (3 mm in thickness) in nanocomposites shows higher performance absorption for C-band (4.65 GHz) with maximum reflection loss of −32.5 dB.

APA, Harvard, Vancouver, ISO, and other styles

7

Bin Asrokin, Azhari, and Mohamad Kamal Bin A. Rahim. "Performance Evaluation of Two Port and Four Port Measurement for Twisted Pair Cable." International Journal of Electrical and Computer Engineering (IJECE) 8, no. 4 (August 1, 2018): 2624. http://dx.doi.org/10.11591/ijece.v8i4.pp2624-2632.

Full text

Abstract:

A balance-unbalance (balun) transformer is commonly used to connect the balance 100 Ohm twisted pair cable to the unbalance 50 Ohm network analyzer ports, but due to the limitations of the core (i.e. ferrite) inside the balun, the balun can only effectively operates at a certain band of frequencies. This limitation can be eliminated by using a 4-port vector network analyzer (VNA) which is done by connecting the VNA’s ports to each conductor end. The extracted S-parameters will then be transformed to a 2-port S-parameters in differential mode at both ports. To validate the measurement technique, S-parameter measurement by using the 4-Port Network Analyzer without any balun will be compared to the measurement which used the 2-Port Network Analyzer with the balun transformers. Two twisted pair cable distances are selected as reference which are 500, and 1000 meters with nominal copper diameter of 0.5mm. Based on the measurement results, the 4-ports measurement shows good correlation with the 2-ports measurement especially at 500m distance. This shows that the 4-ports measurement setup is suitable to be used to measure twisted pair copper cable and possible to measure at a higher frequency band such as up to 500 MHz but at a shorter twisted pair cable distance.

APA, Harvard, Vancouver, ISO, and other styles

8

Schmool, David S., Daniel Markó, Ko-Wei Lin, Aurelio Hierro-Rodríguez, Carlos Quirós, Javier Díaz, Luis Manuel Álvarez-Prado, and Jong-Ching Wu. "Ferromagnetic Resonance Studies in Magnetic Nanosystems." Magnetochemistry 7, no. 9 (September 12, 2021): 126. http://dx.doi.org/10.3390/magnetochemistry7090126.

Full text

Abstract:

Ferromagnetic resonance is a powerful method for the study of all classes of magnetic materials. The experimental technique has been used for many decades and is based on the excitation of a magnetic spin system via a microwave (or rf) field. While earlier methods were based on the use of a microwave spectrometer, more recent developments have seen the widespread use of the vector network analyzer (VNA), which provides a more versatile measurement system at almost comparable sensitivity. While the former is based on a fixed frequency of excitation, the VNA enables frequency-dependent measurements, allowing more in-depth analysis. We have applied this technique to the study of nanostructured thin films or nanodots and coupled magnetic layer systems comprised of exchange-coupled ferromagnetic layers with in-plane and perpendicular magnetic anisotropies. In the first system, we have investigated the magnetization dynamics in Co/Ag bilayers and nanodots. In the second system, we have studied Permalloy (Ni80Fe20, hereafter Py) thin films coupled via an intervening Al layer of varying thickness to a NdCo film which has perpendicular magnetic anisotropy.

APA, Harvard, Vancouver, ISO, and other styles

9

Adamo, Cristina B., Alexander Flacker, Hercílio M. Cavalcanti, Ricardo C. Teixeira, Antonio L. P. Rotondaro, and Leandro T. Manera. "Development of MCM-D Technology with Photosensitive Benzocyclobutene." Journal of Integrated Circuits and Systems 11, no. 1 (December 28, 2016): 19–26. http://dx.doi.org/10.29292/jics.v11i1.426.

Full text

Abstract:

This paper evaluates and compares the development of Multi-Chip Module Deposited (MCM-D) technology using photosensitive benzocyclobutene (BCB) with the non-photosensitive BCB to fabricate passive devices. The polymer was used to isolate the metal/interconnection layers and also as the dielectric for the capacitors. Ni-P/Au was used as the conductor film and Ta2N as the resistor film. The resistors’ sheet resistance was measured with both transfer length method (TLM) and direct measurement while the measurements of the capacitors and inductors required the use of a Vector Network Analyzer (VNA) and some mathematical algorithms.

APA, Harvard, Vancouver, ISO, and other styles

10

Thaher, Raad H., and Noor Baqir Hassan. "Design of P-shaped microstrip patch antenna for wireless communication systems." Indonesian Journal of Electrical Engineering and Computer Science 15, no. 2 (August 1, 2019): 861. http://dx.doi.org/10.11591/ijeecs.v15.i2.pp861-869.

Full text

Abstract:

A P-shaped microstrip patch antenna is proposed and studied to obtain operating bandwidth of (5.883-9.9) GHz. Then the antenna is extended by etching slots in the ground plane to be (5.73 – 10.234) GHz and gain varies from 2.809 dBi to 4.947 dBi. The antenna is installed on FR-4 substrate having relative dielectric constant of = 4.3 and loss tangent of 0.02. The antenna size is (30×30×1.6) simulation results were obtained using CST software 2016. The proposed was fabricated and tested by vector network analyzer VNA and noted reasonable agreement between simulated and measured result.

APA, Harvard, Vancouver, ISO, and other styles

11

Etinger, Ariel, Yosef Golovachev, Ofir Shoshanim, Gad A. Pinhasi, and Yosef Pinhasi. "Experimental Study of Fog and Suspended Water Effects on the 5G Millimeter Wave Communication Channel." Electronics 9, no. 5 (April 27, 2020): 720. http://dx.doi.org/10.3390/electronics9050720.

Full text

Abstract:

Controlled experiments were conducted to examine the effect of fog on signal propagation in wireless communication and radar links operating in millimeter wavelengths. The experiments were carried out in a fog laboratory to verify theoretical results obtained from Liebe’s model. Attenuation and phase shifts of millimeter wave (mmW) radiation were measured, at different fog density characterized by the visibility distance and its water vapor content. Utilizing a vector network analyzer (VNA) enabled us to examine the actual atmospheric attenuation and the phase shift caused by the fog retardation. The experimental results demonstrate good agreement with the simulations even for very low visibility in highly dense fog. The study can be used to estimate link budget of mmW wireless links, including those allocated for the fifth generation (5G) of cellular networks.

APA, Harvard, Vancouver, ISO, and other styles

12

Li and Bhethanabotla. "Design of a Portable Orthogonal Surface Acoustic Wave Sensor System for Simultaneous Sensing and Removal of Nonspecifically Bound Proteins." Sensors 19, no. 18 (September 8, 2019): 3876. http://dx.doi.org/10.3390/s19183876.

Full text

Abstract:

One challenge for current surface acoustic wave (SAW) biosensors is reducing nonspecific adsorption. A device propagating Rayleigh and shear horizontal surface acoustic waves in orthogonal directions fabricated in ST quartz has the capability of achieving simultaneous detection and nonspecific binding (NSB) protein removal. Current measurement methods for a SAW sensor system based on this device require large-size and expensive equipment such as a vector network analyzer (VNA), signal generator, and frequency counter, which are not suitable for portable, especially point-of-care, applications. In this work, a portable platform based on a direct digital synthesizer (DDS) is investigated for the orthogonal SAW sensor, integrating signal synthesis, gain control, phase/amplitude measurement, and data processing in a small, portable electronic system. This prototype was verified for both stability and repeatability, and the results matched very well with VNA measurements. Finally, system performance in real-time sensing and NSB removal was evaluated.

APA, Harvard, Vancouver, ISO, and other styles

13

Sharif, Mahadi, Chew Sue Ping, and Kin Yuen Leong. "Electromagnetic Interference Shielding Performances of MWCNT in Concrete Composites." Solid State Phenomena 266 (October 2017): 283–86. http://dx.doi.org/10.4028/www.scientific.net/ssp.266.283.

Full text

Abstract:

Carbon nanotube (CNT) acts as electromagnetic interference shielding material in concrete composites was presented in this paper. Three concrete samples respectively with different CNT contents were casted and experimentally tested their shielding effectiveness (SE). The SE measurements which were obtained in function of frequency were taken using vector network analyzer (VNA) in the frequency range of 2.4 - 4.0 GHz. The experimental results showed that the CNT contributes to change in conductivity due to the positioning of the electric field of the incident wave and thus, produces different shielding performances. The EMI SE of concrete composites is improved up to 41dB with CNT concentration of 1.5-2.0 wt%.

APA, Harvard, Vancouver, ISO, and other styles

14

Xiao, F., Zhao Xian Xiong, X. Y. Dong, and G. S. Yang. "Automatic Multimode Measurement for Microwave Ceramics." Key Engineering Materials 368-372 (February 2008): 195–97. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.195.

Full text

Abstract:

Automatic measurement system with multimode for microwave ceramic materials is developed. Based on traditional parallel-plate resonance method, the whole system is composed of a parallel-plate cavity, a vector network analyzer (VNA), an interface card for GPIB to USB, and a PC with measurement programs. Besides the fundamental mode, higher order resonant modes are also measured at the same time. Based on a platform of VEE, a set of analysis software is programmed with the functions of not only automatically calibrating and searching resonant frequencies but also automatically computing and displaying the dielectric parameters of microwave materials with high reliability and efficiency in a wide frequency range.

APA, Harvard, Vancouver, ISO, and other styles

15

Liu, Xing, Xian Yan Chen, Yuan Lin, Long Fang Ye, Fen Xiao, and Qing Huo Liu. "A Coaxial Measurement System for Electromagnetic Parameters at Microwave Frequencies." Advanced Materials Research 881-883 (January 2014): 1832–35. http://dx.doi.org/10.4028/www.scientific.net/amr.881-883.1832.

Full text

Abstract:

In this paper, an improved coaxial measurement system with a newly designed coaxial fixture is presented. The electromagnetic parameters of samples are retrieved from the scattering parameters measured by a vector network analyzer (VNA) at microwave frequencies. The measurements of air and PTFE in the range of 1~6 GHz were carried out to verify the reliability and the accuracy of this measurement system. By using frequency-sweep and data processing techniques, the multiplicity of roots is eliminated. The results show that this system can effectively be applied to measure the material electromagnetic parameters of absorbing materials with high accuracy in a wide frequency band.

APA, Harvard, Vancouver, ISO, and other styles

16

Zhang, Shu Yuan, and Quan Xi Cao. "Microwave Absorption Performance of La_0.7 Sr_0.3 MnO₃ with Different Sintering Temperatures." Advanced Materials Research 415-417 (December 2011): 1399–402. http://dx.doi.org/10.4028/www.scientific.net/amr.415-417.1399.

Full text

Abstract:

La 0.7 Sr 0.3 MnO 3 powders have been synthesized at different temperatures by the traditional solid state method. The crystal structures have been characterized by X-ray diffraction (XRD). The electromagnetic parameters were measured by vector network analyzer (VNA) within the frequency range of 5.85-18GHz. It’s found that the pure perovskite structure has been obtained at the temperature of 1000°C. The bandwidth for R<-6dB became thinner with the sintering temperature’s increase from 1000°C to 1150°C, and the absorbing peak moves to the higher frequency first and low frequency then, the absorbing peak is enhanced first and weakened then.

APA, Harvard, Vancouver, ISO, and other styles

17

Handoko, Erfan, Iwan Sugihartono, Mangasi Alion Marpaung, Ucu Cahyana, Sovian Aritonang, Zulkarnain Jalil, Rusmono, et al. "Complex Permittivity, Permeability and Microwave Absorption Studies of Double Layer Magnetic Absorbers Based on BaFe₁₂O₁₉ and BaFe₁₀CoZnO₁₉." Materials Science Forum 966 (August 2019): 302–7. http://dx.doi.org/10.4028/www.scientific.net/msf.966.302.

Full text

Abstract:

Microwave absorption properties of double layer magnetic absorbers based on BaFe12O19 (BFO) and BaFe10CoZnO19 (BFCZO) have been investigated in X-band (8.2–12.4 GHz) frequencies. The BFO and BFCZO were prepared by using a solid state reaction process. The crystalline structures were investigated by X-ray diffraction (XRD), The complex permittivity and permeability are determined using Vector Network Analyzer (VNA) in a range from 8.2 GHz to 12.4 GHz. The double layer magnetic absorbers, composed of the BFO as matching layer and the BFCZO as absorption layer, with a total thickness of 5 mm, showed an effective reflection loss (RL) an effective absorbing bandwidth below –5 dB.

APA, Harvard, Vancouver, ISO, and other styles

18

Lonac, Julio A., Ilan Melczarsky, and Rudi P. Paganelli. "Simple method for characterizing linear multi-port microstrip structures." International Journal of Microwave and Wireless Technologies 3, no. 3 (April 19, 2011): 281–88. http://dx.doi.org/10.1017/s1759078711000481.

Full text

Abstract:

A simple method for the full characterization of passive n-port microwave monolithic integrated circuit (MMIC) structures using standard two-port vector network analyzer (VNA) measurements is presented. Its main advantages are: it does not require to perform measurements from all the ports of the network, no special calibration procedure is needed, the auxiliary terminations required by the procedure can be integrated at the border of the structure under test with minimal area increase, and it can be easily implemented in commercial CAD software. The method was applied to a nine-port microstrip structure corresponding to the output power combiner and impedance matching network of an X-band MMIC high power amplifier (HPA). The full S-parameter matrix was derived from two-port measurements and compared to the circuit–as well as electromagnetic (EM)-based simulations of the structure.

APA, Harvard, Vancouver, ISO, and other styles

19

Peymanfar, Reza, Mitra Rahmanisaghieh, Arezoo Ghaffari, and Yousef Yassi. "Preparation and Identification of BaFe2O4 Nanoparticles by the Sol–Gel Route and Investigation of Its Microwave Absorption Characteristics at Ku-Band Frequency Using Silicone Rubber Medium." Proceedings 2, no. 17 (May 18, 2018): 5234. http://dx.doi.org/10.3390/ecms2018-05234.

Full text

Abstract:

In the last decade, spinel structures have been widely explored due to widespread applications in antibacterial nanocomposites, memory devices, catalysts, photocatalysts, high-frequency devices, and electromagnetic absorbing materials. In this study, BaFe2O4 spinel structures were synthesized through the sol–gel method using a low sintering temperature and were identified by vibrating sample magnetometer (VSM), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FE-SEM), and vector network analyzer (VNA) analysis. Results showed that uniform and pure crystal structures of BaFe2O4 nanoparticles were prepared based on the sol–gel method. Finally, BaFe2O4 nanoparticles were blended by silicone rubber to characterize the microwave absorption properties of the nanocomposite at the ku-band frequency. According to the VNA results, the BaFe2O4/silicone rubber nanocomposite with 1.75 mm thickness absorbed more than 94.38% of microwave irradiation along the ku-band frequency and the maximum reflection loss of the BaFe2O4/silicone rubber nanocomposite was 51.67 dB at 16.1 GHz.

APA, Harvard, Vancouver, ISO, and other styles

20

Chen, Ming-Kun, Cheng-Chi Tai, and Yu-Jung Huang. "Electrical Characterization of FCBGA Package Based on Measurement Approach for High-speed SOC Applications." Journal of Microelectronics and Electronic Packaging 3, no. 4 (October 1, 2006): 216–25. http://dx.doi.org/10.4071/1551-4897-3.4.216.

Full text

Abstract:

With high-speed computers and wireless communications system become more popular in the electronic market, these communication-oriented products require high packaging densities, clock rates and higher switching speeds over Gb/s. A multilayer flip-chip Ball grid array (FCBGA) package used for applications running at more than 1 Gb/s has been characterized in this work. Electrical characterization of the package becomes essential beyond 1 GHz considering that the interconnections on the package behave not only just as interconnections but also as transmission lines. In this paper, we present the measurement and simulation results for interconnection of an FCBGA package using the time domain reflectometry (TDR) method. Simulation and measurement results are compared to establish a proper equivalent circuit model of the FCBGA interconnections. The parasitics of the power network can be measured through TDR, vector network analyzer (VNA) and impedance analyzer (IA). The complete models generated in this work are targeted for high-speed system-on-chip (SOC) devices that have a wide range of uses across commercial electronic applications.

APA, Harvard, Vancouver, ISO, and other styles

21

Tang, Ge Shi, Li Li, Liang Zeng, Lue Chen, and Lv Zhou. "Measurement and Analysis of the Circuit Delay of CEI System." Applied Mechanics and Materials 128-129 (October 2011): 611–15. http://dx.doi.org/10.4028/www.scientific.net/amm.128-129.611.

Full text

Abstract:

By using a four port Vector Network Analyzer (VNA), a caesium clock, a time-interval counter and a signal source to measure the delay of CEI system segmentally. Design measuring methods respectively for three segments of the circuit. When measure the delay, it is found that, delay of antenna’s amplifier output port to the input port of down converter (DC) is stable; the fluctuation of DC’s delay is less than 2ns; the cable delay’s standard deviation is stable at 0.1ns; we get a nanosecond accuracy for whole system. The methods of time delay measurement and the design of CEI system will provide a foundation and primary data for future deep space missions.

APA, Harvard, Vancouver, ISO, and other styles

22

Huang, Yu-Wei, Yu-Jiang Wang, Shi-Cheng Wei, Yi Liang, Wei Huang, Bo Wang, and Bin-Shi Xu. "Preparation of graphene/Fe3O4/Ni electromagnetic microwave absorbing nano-composite materials." International Journal of Modern Physics B 33, no. 01n03 (January 30, 2019): 1940055. http://dx.doi.org/10.1142/s0217979219400551.

Full text

Abstract:

Graphene/Fe3O4/Ni nano-composite materials were prepared by one-step hydrothermal method from RGO, FeCl3 ⋅ 6H2O and purity Ni. The structure and electromagnetic microwave absorbing properties were investigated systematically by field emission scanning electron microscope (FESEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and vector network analyzer (VNA). The reflectance was simulated based on the electromagnetic parameters to evaluate the absorption properties of the sample. The results show that Fe3O4 and Ni are on the surface of graphene evenly, the composites exhibit excellent microwave absorption properties, reflection loss and broad effective absorption bandwidth are −16.38 dB and 3.60 GHz, as the paraffin wax is 40% and the matching thickness is 2.00–3.50 mm.

APA, Harvard, Vancouver, ISO, and other styles

23

Shafiee, Farah Nabilah, Raba’ah Syahidah Azis, Ismayadi Ismail, Rodziah Nazlan, Idza Riati Ibrahim, and Azdiya Suhada Abdul Rahim. "Magnetic and Microwave Properties of Polycrystalline Gadolinium Iron Garnet." Solid State Phenomena 268 (October 2017): 287–91. http://dx.doi.org/10.4028/www.scientific.net/ssp.268.287.

Full text

Abstract:

The microwave loss in nanosized GdIG particles synthesized using mechanical alloying technique was investigated. There were very few of research on the microwave properties of nanosized particle GdIG and there is no attempt investigating on the material at C-band frequency range and its correlation with the microstructure. Gadolinium (III) iron oxide and iron (III) oxide, α-Fe2O3 were used as the starting materials. The mixed powder was then milled in a high-energy ball mixer/mill SPEX8000D for 3 hours. The samples were sintered at temperature 1200°C for 10 hours in an ambient air environment. The phase formation of the sintered samples was analyzed using a Philips X’Pert Diffractometer with Cu-Kα radiation. Complex permeability constitutes of real permeability and magnetic loss factor were measured using an Agilent HP4291A Impedance Material Analyzer in the frequency range from 10 MHz to 1 GHz. A PNA-N5227 Vector Network Analyzer (VNA) was used to obtain the information on ferromagnetic linewidth broadening, ΔH that represents the microwave loss in the samples in in frequency range of 4 to 8 GHz (C-band). The ΔH value was calculated from the transmission (S21) data acquired from VNA. The single phase GdIG showed low initial permeability and low magnetic loss when applied with low-frequency range energy. From these data, it is validated that GdIG is a suitable material for microwave devices for the high-frequency range.

APA, Harvard, Vancouver, ISO, and other styles

24

Sukirman, Engkir, Yosef Sarwanto, Andon Insani, Wisnu Ari Adi, and Yose Fachmi Buys. "Weak Ferromagnetic Property and Electromagnetic Waves Absorption Characteristic of La(1-x)BaxMnO3." International Journal of Engineering Materials and Manufacture 4, no. 3 (September 18, 2019): 96–106. http://dx.doi.org/10.26776/ijemm.04.03.2019.02.

Full text

Abstract:

The weak ferromagnetic property and the electromagnetic waves absorption characteristic of La(1-x)BaxMnO3 (LBMO) compounds have been investigated. The samples of LBMO that are LaMnO3 (S0), La0.9Ba0.1MnO3 (S1); La0.8Ba0.2MnO3 (S2); and La0.7Ba0.3MnO3 (S3) were synthesized using high energy milling (HEM) method. Samples were characterized by means of XRD (X-ray diffractometer), HRPD (high-resolution powder neutron diffractometer), EDS (energy dispersive X-ray spectroscopy, VSM (vibrating sample magnetometer), and VNA (vector network analyzer). There is no magnetic ordering of ferromagnetic in S1 and S2 samples due to the Ba occupation factors of both less than 0.2. The Ba content in the S3 sample is greater than 0.2, hence the ferromagnetic property of the compound is not so visible with the VSM as well as the VNA. The absorption characteristics of electromagnetic waves using VNA indicated that there is an absorption of EM waves in the frequency range between 8-12 GHz with almost the same peak frequency for all four samples at 10.8 GHz with the absorption of around 5 dB. The existence of a weak ferromagnetic property can be detected clearly using HRPD. Neutron diffraction as a probe can observe the magnetic structure accurately even in a material having a weak ferromagnetic property.

APA, Harvard, Vancouver, ISO, and other styles

25

Farhan Affendi bin Yunos, Muhammad, Anis Nurashikin Nordin, Anwar Zainuddin, and Sheroz Khan. "Modeling and development of radio frequency planar interdigital electrode sensors." Bulletin of Electrical Engineering and Informatics 8, no. 3 (September 1, 2019): 985–93. http://dx.doi.org/10.11591/eei.v8i3.1513.

Full text

Abstract:

The interdigital sensor has been implemented in various field of applications such as microwave device, chemical sensor and biological sensor. This work describes the design and fabrication of an interdigital sensor (IDS) design that has the potential of estimating blood glucose levels using capacitive measurements. The IDS was first designed using theoretical equations and later was optimized by using CST Microwave Studio®. The electrode widths of the sensor were varied from 0.5mm to 0.7mm and the S11 reflection characteristics were simulated.Upon completion of simulations, the sensor was fabricated using copper clad FR4 boards. The fabricated sensors were measured using a vector network analyzer (VNA) and produced resonance frequencies of 2.02, 2.11 and 2.14 GHz. The highest Q obtained was 11.72 from the 2.11 GHz sensor.

APA, Harvard, Vancouver, ISO, and other styles

26

Handoko, Erfan, Iwan Sugihartono, Mangasi Alion Marpaung, Ucu Cahyana, Sovian Aritonang, Zulkarnain Jalil, Rusmono, Ahmad Taufiq, Sunaryono, and Mudrik Alaydrus. "Enhanced Microwave Absorbing Capabilities of Multilayer Absorbers Based on BaFe₁₂O₁₉ and Fe₃O₄." Materials Science Forum 966 (August 2019): 338–43. http://dx.doi.org/10.4028/www.scientific.net/msf.966.338.

Full text

Abstract:

In order to enhance a new microwave absorbing capabilities in the X-band frequency range, polycrystalline magnetic materials of BaFe12O19 barium hexaferrite were fabricated through conventional ceramic method and the Fe3O4 powder from iron sand were prepared through magnetic separation after milling process by using planetary ball mill. Microwave absorbing capabilities of multilayer absorbers, composed of BaFe12O19 barium hexaferrite and the Fe3O4 powder, with a total thickness of 10 mm, were investigated by a vector network analyzer (VNA) in the range of 8.2 –12.4 GHz. According to transmission line theory, reflection of microwave radiations from multilayer magnetic materials is calculated. The reflection loss (RL) strongly depends on thickness of multilayer absorbers and showed an optimal RL. Keywords : BaFe12O19, Fe3O4 powder, reflection loss, multilayer absorbers.

APA, Harvard, Vancouver, ISO, and other styles

27

Sun, Hai Tao, Sa Zhang, Hui Yong Deng, Kai Bo Cui, and Fang Zhao. "Microwave Absorption Properties of Porous Co/C Nanofibers Synthesized by Electrospinning." Materials Science Forum 975 (January 2020): 133–38. http://dx.doi.org/10.4028/www.scientific.net/msf.975.133.

Full text

Abstract:

Porous Co/C composite nanofibers were fabricated by combination of electrospinning method and polymer blend. The phase composition, microstructure and electromagnetic characteristics of them were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and vector network analyzer (VNA), and their microwave absorption performances were studied. The results indicate that nanofibers were composited by amorphous carbon and face-centered cubic structured Co nanoparticle after sintering. The addition of PMMA is a key factor of nanofibers morphology and the aperture was improved with the increase of PMMA. When the thickness is 2.0 mm, the samples exhibit the best microwave absorption performance. Their effective absorpt ion bandwidths (RL < 10 dB) are 6.3 GHz, 6.2 GHz and 6.1 GHz, and it’s obviously superior to ordinary morphology nanofibers.

APA, Harvard, Vancouver, ISO, and other styles

28

Carro, Pedro Luis, Jesús de Mingo, Paloma García-Dúcar, and Antonio Valdovinos. "Statistical Antenna Proximity Effect Modeling with Uncertainty Impedance Ellipses." International Journal of Antennas and Propagation 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/7192491.

Full text

Abstract:

User effects on portable antennas can decrease the global terminal performance, such as reducing the battery life or the wireless coverage. People presence will modify the input impedance, the far field radiation pattern, the radiation efficiency, and the near field. In this paper, we investigate the influence of the user on the input impedance by means of a new statistical approach which relies on uncertainty, where a handheld antenna works in two modes (data and talk) while people couple to the antenna. Studying some reflection coefficient measurements performed with a vector network analyzer (VNA), a standard framework based on uncertainty ellipses is developed. Finally, the method is applied to some antenna prototypes, showing its advantages and reliability to quantify and compare proximity effects.

APA, Harvard, Vancouver, ISO, and other styles

29

Kumar, Abhishek, Vijaya Agarwala, and Dharmendra Singh. "Effect of Mg Substitution on Microwave Absorption of BaFe₁₂O₁₉." Advanced Materials Research 585 (November 2012): 62–66. http://dx.doi.org/10.4028/www.scientific.net/amr.585.62.

Full text

Abstract:

The Magnesium substituted barium hexaferrites were prepared by sol-gel auto-combustion method according to the molecular formula BaMgxFe(12−x)O19 (x=0, 0.5 and 1). The crystalline structure, morphology, complex permittivity, and complex permeability were measured with X-ray Diffraction (XRD), Field Emission-Scanning Electron Microscopy (FE-SEM) and Vector Network Analyzer (VNA) respectively. From XRD study, the formations of single phase ultrafine particles have been confirmed. The XRD analysis showed that variation in lattice parameter with change in x value. The FE-SEM study shows that synthesized particles have hexagonal morphology. The minimum reflection loss of -24.86 dB at 9.04 GHz was found with the increase in band width at x=1, which suits its application as RADAR absorbing materials.

APA, Harvard, Vancouver, ISO, and other styles

30

Marinković, Zlatica, Giovanni Gugliandolo, Mariangela Latino, Giuseppe Campobello, Giovanni Crupi, and Nicola Donato. "Characterization and Neural Modeling of a Microwave Gas Sensor for Oxygen Detection Aimed at Healthcare Applications." Sensors 20, no. 24 (December 13, 2020): 7150. http://dx.doi.org/10.3390/s20247150.

Full text

Abstract:

The studied sensor consists of a microstrip interdigital capacitor covered by a gas sensing layer made of titanium dioxide (TiO2). To explore the gas sensing properties of the developed sensor, oxygen detection is considered as a case study. The sensor is electrically characterized using the complex scattering parameters measured with a vector network analyzer (VNA). The experimental investigation is performed over a frequency range of 1.5 GHz to 2.9 GHz by placing the sensor inside a polytetrafluoroethylene (PTFE) test chamber with a binary gas mixture composed of oxygen and nitrogen. The frequency-dependent response of the sensor is investigated in detail and further modelled using an artificial neural network (ANN) approach. The proposed modelling procedure allows mimicking the measured sensor performance over the whole range of oxygen concentration, going from 0% to 100%, and predicting the behavior of the resonant frequencies that can be used as sensing parameters.

APA, Harvard, Vancouver, ISO, and other styles

31

Zubair, Khadija, and Muhammad Fayzan Shakir. "Effect of Polymer Matrix in Polymer/trGO Nano-Composite for EMI Shielding Application in Microwave and Infrared Region." Key Engineering Materials 875 (February 2021): 153–59. http://dx.doi.org/10.4028/www.scientific.net/kem.875.153.

Full text

Abstract:

Thermally reduced graphene oxide (trGO) was successfully prepared and confirmed by XRD then dispersed in polystyrene (PS) and Acrylonitrile-Butadiene-Styrene (ABS) polymers and evaluated for EMI shielding in microwave and infrared (IR) region. Thickness of prepared polymer/trGO composite films were 200-250 micron. It was observed that trGO has more compatibility with PS then ABS and dispersed more easily and uniformly in PS than ABS. This effect was also observed in IR shielding as ABS+15trGO have 3% transmission and PS+1% trGO have 1.5% transmission. Maximum 29 dB and 25 dB shielding effectiveness was measured by vector network analyzer (VNA) in microwave region (9-18 GHz) of PS+2% trGO and ABS+2% trGo composite respectively. These results clearly indicating that trGO is more compatible with PS than ABS and form more stable and mature interconnected network structure in PS at lower concentrations.

APA, Harvard, Vancouver, ISO, and other styles

32

Saini, Monika, Nidhi Sheoran, Rajni Shukla, Tanuj Kumar, and S. K. Singh. "A Comparative study of Structural, Thermal and Conducting properties of Polyaniline, Polypyrrole and Poly (Ani-co-Py) Copolymer." MRS Advances 4, no. 28-29 (2019): 1639–48. http://dx.doi.org/10.1557/adv.2019.249.

Full text

Abstract:

ABSTRACTConducting polymers namely polyaniline (PANI), polypyrrole (PPy) and their copolymer poly(Aniline-co-Pyrrole)(PAPY) were prepared via in-situ polymerization process. The X-ray diffraction (XRD), infra-red (IR)and field emission-scanning electron microscopy (FESEM) studies confirm the formation of polyaniline, polypyrrole and their copolymer with aniline and pyrrole. The XRD pattern of copolymer displayed an amorphous structure as compared to polycrystalline homopolymers. FE-SEM results of Poly (Ani-co-Py) shows the existence of agglomerated spherical structured particles in the copolymer matrix, while the polyaniline and polypyrrole exhibit the porous tubular and spherical structures, respectively. Thermo gravimetric analysis (TGA) shows that the copolymer is more stable as compared to their homopolymers at higher temperature. Four probe resistivity (FPR) studies indicate that copolymer has the lower conductivity and act as a diode. Vector network analyzer (VNA) measurements observe a significant shielding effectiveness (SE) for all the conducting polymers.

APA, Harvard, Vancouver, ISO, and other styles

33

Chen, Yue Guang, Gui Fang Liu, and Shi Jiao Wang. "Effect of Polyvinyl Pyrrolidone Dosage on Barium Ferrite Fibers via Electrospinning." Materials Science Forum 848 (March 2016): 333–38. http://dx.doi.org/10.4028/www.scientific.net/msf.848.333.

Full text

Abstract:

Barium ferrite micro/nanofibers were successfully prepared via the electrospinning by using dimethyl formamide (DMF) as the solvent, poly vinyl pyrrolidone (PVP) as the spinning auxiliaries and iron nitrate and barium nitrate as raw materials. The effect of poly vinyl pyrrolidone on the structure, morphology, magnetic and microwave absorbing properties were investigated by scanning electron microscope (SEM), X-ray diffraction analysis (XRD), vibration sample magnetometer (VSM) and vector network analyzer (VNA). XRD patterns of the samples confirmed that when the additive content of PVP was up to 10%, (wt%) pure barium ferrite fibers formed under the condition of the same heat treatment. Also, the FE-SEM images showed that the morphology of the fibers improved with the increase of PVP content. Moreover, the VSM results demonstrated that the saturation magnetization can reach 54.7 emu/g when the PVP dosage is 14% (wt%) in the precursor solution.

APA, Harvard, Vancouver, ISO, and other styles

34

Huang, Hui, Xin Meng Liu, and Xin Lv. "Accuracy Improvement for Scattering-Parameters Evaluating of Microwave Coplanar Probe Using One-Port Two-Tier Multi-TRL Calibration Method." Applied Mechanics and Materials 333-335 (July 2013): 254–58. http://dx.doi.org/10.4028/www.scientific.net/amm.333-335.254.

Full text

Abstract:

This paper presents a method improving accuracy for evaluating S-parameters (Scattering-parameters) of MCP (Microwave Coplanar Probe). This method may be named one-port two-tier Multi-TRL (Thru-Reflect-Line) calibration method. It measures two-port devices only at one port of VNA (Vector Network Analyzer). It decreases the random errors caused of cable movements and connecting times. This method is implemented with coaxial OSL (Open-Short-Load) and on-wafer TRL calibration kit. It directly calculates and removes the residual errors caused of coaxial OSL calibration kit imperfection. It significantly reduced system errors by using on-wafer TRL calibration kit. To verify the effectiveness of the proposed method, the measured S-parameters up to 50GHz of MCP configured with GSG-100 are given and discussed.

APA, Harvard, Vancouver, ISO, and other styles

35

Soleimani, Hasan, Noorhana Yahya, Zulkifly Abbas, Hojjatollah Soleimani, and Hasnah Mohd Zaid. "Determination Reflection and Transmission Coefficients of Lanthanum Iron Garnet Filled PVDF-Polymer Nanocomposite Using Finite Element Method Modeling at Microwave Frequencies." Journal of Nano Research 21 (December 2012): 151–57. http://dx.doi.org/10.4028/www.scientific.net/jnanor.21.151.

Full text

Abstract:

In our previous work, the lanthanum iron garnet-filled PVDF-polymer nanocomposite has been prepared. The reflection and transmission coefficients of PVDF/LIG were measured using rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) at X-band frequencies (8 GHz - 12 GHz). In this study, the distribution of electric field intensity of PVDF/ LIG which was loaded in rectangular waveguide was simulated based on Finite Element Method (FEM) formulation to show the essential differences of intensity of emitted electrical field. The computations of reflection and transmission coefficients of PVDF/ LIG were determined by using implementation FEM modeling rectangular waveguide. The FEM results were compared with the experimental achievement results using the rectangular waveguide. An excellent agreement between measured and simulated results was obtained based on the values of mean relative errors.

APA, Harvard, Vancouver, ISO, and other styles

36

Zhang, Shu Yuan, and Quan Xi Cao. "Microwave Absorbing Performance and Infrared Emissivity of Co-Doped ZnO." Advanced Materials Research 399-401 (November 2011): 880–85. http://dx.doi.org/10.4028/www.scientific.net/amr.399-401.880.

Full text

Abstract:

In this paper the powders of Zn1-xCoxO (x=0, 0.01, 0.02, 0.025, 0.05, 0.1) were fabricated by the conventional solid state reaction. The crystal structure was characterized by x-ray diffraction (XRD). The electromagnetic parameters were measured using vector network analyzer (VNA), the infrared emissivity in the wavelength range of 3-5μm and 8-14μm was measured by Dual-band infrared emissivity measuring instrument. The absorption bandwidth of the double-layer microwave absorber is obviously more than that of the single-layer absorber. The bandwidth of the double-layer microwave absorber for reflection loss R<-8dB is 2.64GHz over the range of 8.2-18GHz. The thickness of the absorbers is only 4 mm. The infrared emissivity is only 0.39 in the range of 3-5μm and 0.81 in the range of 8-14μm.

APA, Harvard, Vancouver, ISO, and other styles

37

Yang, Chuang. "A Position-Independent Reflection-Only Method for Complex Permittivity and Permeability Determination with One Sample." Frequenz 74, no. 3-4 (March 26, 2020): 163–67. http://dx.doi.org/10.1515/freq-2019-0062.

Full text

Abstract:

AbstractThis paper presents a position-independent reflection-only method for determining complex permittivity and permeability of a sample. In this method, both the short and match calibration kits are used to measure the reflection coefficients. Only one sample positioned arbitrarily is measured using a one-port vector network analyzer (VNA), while the complex permittivity and permeability of the sample are determined simultaneously. Experimental results in X-band for the Acrylonitrile Butadiene Styrene plastic (ABS) are included to exhibit the validity of the proposed method. The results show that the complex permittivity and permeability determined by the proposed method have a good agreement with the parameters determined by the well-known Nicolson–Ross–Weir (NRW) method. In addition, a magnetic material is simulated to further validate the proposed method.

APA, Harvard, Vancouver, ISO, and other styles

38

Soleimani, Hassan, Noorhana Yahya, Kamyar Shameli, Zulkifly Abbas, Lee Kean Chuan, and Jamshed Amighian. "S-Parameters of Bismuth Iron Garnet (BIG) Filled Polyvinylidene Fluoride Composite Using Rectangular Waveguide Method." Advanced Materials Research 1024 (August 2014): 15–18. http://dx.doi.org/10.4028/www.scientific.net/amr.1024.15.

Full text

Abstract:

Nanosized Bismuth Iron Garnet (BIG) was synthesized via sol-gel method. The nanomaterials with ferrite structure were heat-treated at different temperatures from 700 to 1100 °C. The structure and morphology were characterized by Powder X-ray diffraction (PXRD) and Scanning electron microscope (SEM), respectively. The PXRD show that with the increase of temperature the size of crystallites for BIG gradually increased. The BIG ferrite nanopowder was composited with polyvinylidene fluoride (PVDF) by solution casting method with different ferrite ratios. The magnitudes of S-parameters of PVDF/BIG were investigated using rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) at microwave frequencies. The S-parameters of PVDF/BIG are found to be slightly different from those of ferrite contents in polymer composites. The S11is found to be increased by increasing the ferrite content of the composites as well as with frequency while the S21is observed to decrease with increase in ferrite content.

APA, Harvard, Vancouver, ISO, and other styles

39

Yin, Zhang, Wang, Feng, Zhao, Rao, Wang, and Dai. "Preparation of SiO2-MnFe2O4 Composites via One-Pot Hydrothermal Synthesis Method and Microwave Absorption Investigation in S-Band." Molecules 24, no. 14 (July 17, 2019): 2605. http://dx.doi.org/10.3390/molecules24142605.

Full text

Abstract:

MnFe2O4 NPs are successfully decorated on the surface of SiO2 sheets to form the SiO2-MnFe2O4 composite via one-pot hydrothermal synthesis method. The phase identification, morphology, crystal structure, distribution of elements, and microwave absorbing properties in S-band (1.55~3.4 GHz) of the as-prepared composite were investigated by XRD, SEM, TEM, and Vector Network Analyzer (VNA) respectively. Compared with the pure MnFe2O4 NPs, the as-prepared SiO2-MnFe2O4 composite exhibits enhanced microwave absorption performance in this frequency band due to the strong eddy current loss, better impedance matching, excellent attenuation characteristic, and multiple Debye relaxation processes. The maximum reflection loss of −14.87 dB at 2.25 GHz with a broader −10 dB bandwidth over the frequency range of 1.67~2.9 GHz (1.23 GHz) can be obtained at the thickness of 4 mm. Most importantly, the preparation method used here is relatively simple, hence such composite can be served as a potential candidate for effective microwave absorption in S-band.

APA, Harvard, Vancouver, ISO, and other styles

40

Shaikh, Faraz Ahmed, Sheroz Khan, Zarimin Zaharudin, AHM Zahirul Alam, Farah Diyana Bt Abdul Rahman, Khairayu Bt Badron, Dominique Baillargeat, Mashkuri Bin Yaacob, and Zeeshan Shahid. "Recognition of Metal Objects inside Wall using Antipodal Vivaldi Antenna." Indonesian Journal of Electrical Engineering and Computer Science 11, no. 1 (July 1, 2018): 27. http://dx.doi.org/10.11591/ijeecs.v11.i1.pp27-35.

Full text

Abstract:

This paper present a recognition technique of metal placed inside and between two walls. A unique scheme of recognition of metallic objects through Ultra Wide Band (UWB) Modified Antipodal Vivaldi Antenna (MAVA) frequency range of (3.1GHz to 10.6 GHz) is presented in this paper.The working mechanism of detection system based on Time Domain Reflectrometry (TDR) using through wall imaging (TWMI). A very small duration pulses generated by Vector Network Analyzer (VNA) which are used for illuminate the wall.The analysis of a system under UWB antenna probe array. The simulation results of MAVA have given an enormous potential of penetration, in order to recognize concealed metal objects with fine precision, proving a smart development in the detection system technology. The improvement of resolution in an image, special filters have been developed and implemented. The design and optimization progression is conceded out via CST simulation software for parametric performance assessment of return loss, radiation pattern and directivity.

APA, Harvard, Vancouver, ISO, and other styles

41

Rolfes, I., and B. Schiek. "An Error Correction Procedure for Multi-Port Measurements at High Frequencies." Advances in Radio Science 3 (May 12, 2005): 59–64. http://dx.doi.org/10.5194/ars-3-59-2005.

Full text

Abstract:

Abstract. The multi-port method for the measurement of the scattering parameters of multi-ports with the help of a vector network analyzer (VNA) with only two measurement ports is presented. For the measurements only two ports of the N-port device can be connected to the two ports of the VNA at a time. The remaining N-2 ports of the device under test (DUT) are connected to external terminations. As these external terminations might be mismatched, the measured scattering parameters depend on the reflective characteristics of the terminations. An error correction becomes necessary in order to calculate the effective scattering parameters of the DUT (Tippet and Speciale, 1982; Lu and Chu, 2003). In contrast to the correction method of Tippet and Speciale (1982), the multi-port method has the advantage, that the external terminations can be chosen arbitrarily. Thus, a realization as an open or short circuit is possible as well. Furthermore, the terminations can be unknown except for one, similar to self-calibration procedures of VNAs. This helps to improve the accuracy of the measurements, because the inconsistency problem due to a slightly erroneous knowledge of the frequency characteristics of the terminations can be eliminated.

APA, Harvard, Vancouver, ISO, and other styles

42

Shrestha, Bijaya. "Design of Low Noise Amplifier for 1.5 GHz." SCITECH Nepal 13, no. 1 (September 30, 2018): 40–47. http://dx.doi.org/10.3126/scitech.v13i1.23500.

Full text

Abstract:

Low Noise Amplifier (LNA) is a front-end device of a radio frequency (RF) receiver used to increase the amplitude of an RF signal without much additional noise, thereby increasing the noise figure of the system. This paper presents design, simulation, and prototype of an LNA operating at 1.5 GHz for the bandwidth of 100 MHz. The circuit was simulated using Advanced Design System (ADS). The components used are Surface Mount Devices (SMDs); with transistor "Infineon BFP420" as a major component. Other components are resistors, capacitors, and inductors; inductors being superseded by microstrip lines. The circuit was fabricated on FR4 board. The measurements of several parameters of LNA were made using Vector Network Analyzer (VNA), Noise Figure Meter; and Spectrum Analyzer. The LNA has minimum gain of 15.4 dB and maximum noise figure of 1.33 dB. It is unconditionally stable from 50 MHz to 10 GHz. DC supply is 5V and the current consumption is 10 mA. This LNA offers Output-ThirdOrder-Intercept-Point (OJP3) of about 1 4 dBm.

APA, Harvard, Vancouver, ISO, and other styles

43

Chen, Hui, Di Jiang, Ke-Song Chen, and Hong-Fei Zhao. "A Compact High-Pass Filter Using Hybrid Microstrip/Nonuniform CPW with Dual-Mode Resonant Response." International Journal of Antennas and Propagation 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/1940850.

Full text

Abstract:

A novel and miniature high-pass filter (HPF) based on a hybrid-coupled microstrip/nonuniform coplanar waveguide (CPW) resonator is proposed in this article, in which the designed CPW has exhibited a wideband dual-mode characteristic within the desired high-pass frequency range. The implemented filter consists of the top microstrip coupled patches and the bottom modified nonuniformly short-circuited CPW resonator. Simulated results from the electromagnetic (EM) analysis software and measured results from a vector network analyzer (VNA) show a good agreement. A designed and fabricated prototype filter having a 3 dB cutoff frequency (fc) of 5.78 GHz has shown an ultrawide high-pass behavior, which exhibits the highest passband frequency exceeding 4.0fcunder the minimum insertion loss (IL) 0.75 dB. The printed circuit board (PCB) area of the filter is approximately0.062λg×0.093λg, whereλgis the guided wavelength atfc.

APA, Harvard, Vancouver, ISO, and other styles

44

Maharjan, Ram Krishna. "Microstrip Compact Twin-Interdigital Steped Impedance Resonator-Based Bandpass Filter for C-Band Applications." Journal of Advanced College of Engineering and Management 4 (December 31, 2018): 119–24. http://dx.doi.org/10.3126/jacem.v4i0.23201.

Full text

Abstract:

This research focuses a new microstrip twin-interdigital type bandpass filter based on stepped impedance resonator (SIR) structure. The proposed structure consists of two slightly different interdigital capacitances within a single SIR resonator that behaves as a bandpass filter (BPF) of center frequency 4.3 GHz with 700 MHz bandwidth at 3 dB pass band. This design is not only subjected to size reduction, but also low pass-band insertion loss and high return loss as well. The Sonnet software tool has been used to design and simulate the microstrip BPF. The fabricated BPF was measured using the Agilent 8510C vector network analyzer (VNA) and achieved the insertion loss of 0.5 dB and the return loss of 26 dB. The measured results were compared with those simulated results which were very close to each other. The fabricated BPF can be used for Cband Applications.

APA, Harvard, Vancouver, ISO, and other styles

45

Peter, Ronny, and Gerhard Fischerauer. "Homodyne vector network analysis as a tool for the real-time measurement of electrical material parameter distributions in the field." tm - Technisches Messen 87, no. 3 (March 26, 2020): 177–88. http://dx.doi.org/10.1515/teme-2019-0139.

Full text

Abstract:

AbstractThe spatial distribution of electrical material parameters (e. g. permittivity and conductivity) can be a valuable indicator of the state of a chemical process or the condition of the processing system. Unfortunately, there are very few measurement systems that could handle this task in the field at low cost and with small shape factors. A potential solution currently under research for the determination of material parameter distributions is based on electromagnetic resonances inside chemical reactors. In the laboratory, vector network analyzers (VNA) and personal computers are used, which is expensive. This contribution reports on an application-specific stand-alone homodyne VNA with integrated data processing as an effort to transfer the laboratory-proven method to the field. The quality of the approach, validated by comparison with commercial VNAs, is shown to suffice for typical field applications.

APA, Harvard, Vancouver, ISO, and other styles

46

Tiwari, Madhvi, M. A. Arya, Priyesh V. More, Saurabh Parmar, Suwarna Datar, and Pawan K. Khanna. "Co/Co3O4 Based Nanoparticles and Their Polymer Composites for Tuned Electromagnetic Interference Shielding Application." Journal of Nanoscience and Nanotechnology 20, no. 5 (May 1, 2020): 2847–57. http://dx.doi.org/10.1166/jnn.2020.17474.

Full text

Abstract:

The magnetic properties of the metal nanoparticles (NPs) can play remarkable role in electromagnetic interference shielding (EMI Shielding) of many defence and commercial electronic devices. In the present work, coconut oil and PVA capped magnetic cobalt/cobalt oxide nanoparticles (Co/Co3O4 NPs) were synthesized by chemical reduction method and impregnated in polymer matrix to verify their EMI shielding behaviour. The coconut oil capped Co/Co3O4 NPs with presence of hcp and fcc phases were prepared in the size domain of 7–10 nm and the effect of surfactant (the oil) on size and oxidation state was studied by varying the ratios. The shielding efficiencies of Co/Co3O4 NPs PVA nanocomposites were analysed by using vector network analyser (VNA) in X- and Ku-band ranging from 8 GHz–18 GHz. The VNA results showed increased shielding efficiency with increasing concentration of NPs.

APA, Harvard, Vancouver, ISO, and other styles

47

Harry, Sucitra, Zahriladha Zakaria, Maizatul Said, Rammah Alahnomi, and M. Misran. "Design of Dual Band Meta-Material Resonator Sensor for Material Characterization." Applied Computational Electromagnetics Society 36, no. 4 (May 10, 2021): 473–78. http://dx.doi.org/10.47037/2020.aces.j.360414.

Full text

Abstract:

This paper describes the design and implementation of the dual band metamaterial resonator for sensing applications by employing perturbation theory in which the dielectric properties of resonator affect Q-factor and resonance frequency. The designed sensor operates at two resonance frequency 3.20 GHz and 4.18 GHz in the range of 1 GHz to 5.5 GHz for testing solid materials. The Computer Simulation Technology (CST) software is used to design and model this sensor and it was analyzed by using vector network analyzer (VNA) for testing measurement. This study uses empirical equation from the tested materials with well-known permittivity to estimate the permittivity of other materials with unknown permittivity. The proposed sensor has achieved a narrow band with high Q-factor value of 642 and 521 at the operating frequencies of 3.16 GHz and 4.18 GHz respectively. These findings are compared with findings of previous study and the proposed sensor has achieved a high sensitivity and accuracy of 80% compare to others. This is proof that this senor could be used to characterize materials and sensing applications.

APA, Harvard, Vancouver, ISO, and other styles

48

Shakir, Muhammad Fayzan, and Asra Tariq. "EMI Shielding Properties of Polymer Blend with the Inclusion of Graphene Nano Platelets." Key Engineering Materials 875 (February 2021): 160–67. http://dx.doi.org/10.4028/www.scientific.net/kem.875.160.

Full text

Abstract:

Polymer nano composites based on poly vinyl chloride matrix were fabricated using polyaniline (PANI) and graphene nano platelets (GNP) as electrically conductive nano filler for the application of electromagnetic interference (EMI) shielding. DC conductivity was first evaluated by using cyclic voltammetry and found an increasing trend of electrical conductivity as PANI and GNP was added in PVC matrix that confirms the formation of electrically conductive network structure. Dielectric properties like dielectric constant, dielectric loss and AC conductivity were evaluated in frequency range of 100 Hz to 3 MHz that gives basic prediction for EMI shielding effectiveness. Vector Network Analyzer (VNA) was used to assess EMI shielding properties using coaxial cable method in 11GHz to 20GHz range and it was found that a maximum of 29 dB shielding was archived with the incorporation of 15 wt% of PANI in PVC. This value increased to 56 dB as 5 wt% GNP added in PVC/PANI 15 wt% blend. Interaction of matrix with filler, nature of filler and dispersion of filler in matrix are the key parameters for achieving high shielding effectiveness.

APA, Harvard, Vancouver, ISO, and other styles

49

Gao, Lan, Chiara Dachena, Kaijun Wu, Alessandro Fedeli, Matteo Pastorino, Andrea Randazzo, Xiaoping Wu, and Sébastien Lambot. "Full-Wave Modeling and Inversion of UWB Radar Data for Wave Propagation in Cylindrical Objects." Remote Sensing 13, no. 12 (June 17, 2021): 2370. http://dx.doi.org/10.3390/rs13122370.

Full text

Abstract:

The nondestructive characterization of cylindrical objects is needed in many fields, such as medical diagnostics, tree trunk inspection, or concrete column testing. In this study, the radar equation of Lambot et al. is combined with cylindrical Green’s functions to fully model and invert ultra-wideband (UWB) ground-penetrating radar (GPR) data and retrieve the properties of cylindrical objects. Inversion is carried out using a lookup table (LUT) approach followed by local optimization to ensure retrieval of the global minimum of the objective function. Numerical experiments were conducted to analyze the capabilities of the developed inversion procedure to estimate the radius, permittivity, and conductivity of the cylinders. The full-wave model was validated in laboratory conditions on metallic and plastic pipes of different sizes. The adopted radar system consists of a lightweight vector network analyzer (VNA) connected to a single transmitting and receiving horn antenna. The numerical experiments highlighted the complexity of the inverse problem, mainly originating from the multiple propagation modes within cylindrical objects. The laboratory measurements demonstrated the accuracy of the forward modeling and reconstructions in far-field conditions.

APA, Harvard, Vancouver, ISO, and other styles

50

Navarrini, Alessandro, and Renzo Nesti. "Characterization Techniques of Millimeter-Wave Orthomode Transducers (OMTs)." Electronics 10, no. 15 (July 31, 2021): 1844. http://dx.doi.org/10.3390/electronics10151844.

Full text

Abstract:

We report on advanced techniques for the accurate characterization of millimeter-wave Orthomode Transducers (OMTs) enabling the derivation of the fundamental parameters of such devices, i.e., the insertion loss, the return loss, the cross-polarization, and the isolation. These techniques include standard frequency-domain and time-domain VNA (Vector Network Analyzer) measurement methods, which can be applied to remove the effects of the waveguide transitions necessary to access the OMT ports and excite the desired modes. After reviewing the definition of the OMT parameters, we discuss the test equipment, the VNA calibration procedures as well as the VNA time-domain time-gating method for application in OMT characterization. We present simplified equations that relate the calibrated VNA measured quantities with the OMT S-parameters, illustrate various characterization methods, and examine various OMT experimental test setups. The advantages and disadvantages of each of the OMT characterization procedures are presented and compared among them. We provide a list of waveguide components required in the OMT test setups (adapters, loads, quarter-wave and longer waveguide sections, feed-horn, etc.), discuss the error terms introduced by such components and examine their impact on the measured values. Furthermore, we identify strategies to mitigate or remove the effects of the measured errors, to derive the desired OMT parameters. Different OMT configurations, with a distinct orientation of the waveguide input and outputs, are discussed. Although the presented techniques refer to the characterization of a specific configuration of a W-band OMT, the described methods can be applied to other OMT configurations and frequency ranges (from microwave to THz frequencies), therefore having a general validity.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Vector network analyzer (VNA)'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles