Academic literature on the topic 'PIFA antenna design'

This thesis focuses on mobile phones antenna design with brief description about the historical development, basic parameters and the types of antennas which are used in mobile phones. Mobile phones antenna design section consists of two proposed PIFA antennas. The first design concerns a single band antenna with resonant frequency at GPS frequency (1.575GHz). The first model is designed with main consideration that is to have the lower possible PIFA single band dimensions with reasonable return loss (S11) and the efficiencies. Second design concerns in a wideband PIFA antenna which cover the range from 1800MHz to 2600MHz. This range covers certain important bands: GSM (1800MHz & 1900MHz), UMTS (2100MHz), Bluetooth & Wi-Fi (2.4GHz) and LTE system (2.3GHz, 2.5GHz, and 2.6GHz). The wideband PIFA design is achieved by using slotted ground plane technique. The simulations for both models are performed in COMSOL Multiphysics.  The last two parts of the thesis present the problems of mobile phones antenna. Starting with Specific absorption rate (SAR) problem, efficiency of Mobile phones antenna, and hand-held environment.

The beginning of the 21 st century is characterised, among others, by the evolution in telecommunications. The rapid growth of mobile communications and the variety of applications proposed for the third generation (3G) systems require long operation time, low weight and cost for terminals, as well as improved link quality. For this reason a good efficiency and low profile antennas with low absorption losses by the user are desirable. The Planar Inverted-F Antenna (PIFA) is shown to result into low SAR values and high efficiency when operating in the proximity of the user. Despite these advantages, PIFA is also characterised by narrow bandwidth that limits its practical use. The first part of this work is dedicated to the measurements and evaluation of the radiation characteristics of the PIFA and other wire antennas both in the near and far fields. In addition, novel methods of PIFA tuning are presented. These include the repositioning of the shorting pin and modification of its capacitance. By using these techniques, the effective bandwidth of the PIFA can be increased to satisfy the GSM900 and DCS 1800 system bandwidth requirements. Dual-band and electronically tuned PIFA prototypes are also included. The effects of the handset size on the mass averaged Specific Absorption Rate (SAR), and antenna efficiency are investigated. The appropriate choice of handset can result in up to 30%-reduced peak SAR. The computed SAR values from PIFA are compared with those resulting from the use of a handset equipped with quarter wavelength monopole antenna. A new measure referred to as the 3dB SAR volume is proposed. This measure provides better understanding of the absorbed power distribution in the operator's head. Results obtained in the course of study show that low profile handset antennas, such as the PIFA, present in addition to dual resonance and low reflection losses, reduced SAR values, high efficiency and low 3dB SAR volume. Finally, SAR and 3dB SAR volume values from simulations on 5- and 10- years old child head models are compared with their equivalents for adult models from which appropriate conclusions are drawn.

The rapidly growing demand for UWB as high data rates wireless communications technology, since the Federal Communications Commission (FCC) allocated the bandwidth of UWB from 3.1GHz to 10.6 GHz. Antenna also plays an essential role in UWB system. However, there are some difficulties in designing UWB antenna as compared to narrowband antenna. The primary requirement of UWB antennas is be able to operate over frequencies released by the FCC. Moreover, the satisfaction of radiation properties and good time domain performance over the entire frequency range are also necessary. In this thesis, designing and analysing printed crescent shape monopole antenna, Planar Inverted F-L Antenna (PIFLA) and Planar Inverted FF Antenna (PIFFA) are focused. A Planar Inverted FF Antenna (PIFFA) can be created to reduce the potential for interference between a UWB system and other communications protocols by using spiral slot. The antennas exhibits broadside directional pattern. The performances such as return loss, radiation pattern and current distribution of the UWB antennas are extensively investigated and carried out. All the results have been demonstrated using simulation and experimentally whereby all results satisfy the performance under - 10dB point in the bandwidth of UWB. In addition the miniaturization of MIMO/diversity Planar Inverted-F antenna (PIFA) which is suitable for pattern diversity in UWB applications is presented. This antenna assembly is formed by two identical PIFAs, a T-shaped decoupling structure which connects the two PIFAs and a finite ground plane with a total compact envelope dimension of 50 ¿ 90 ¿ 7.5mm3. The radiation performance of the proposed MIMO antenna was quite encouraging and provided an acceptable agreement between the computed and measured envelope correlation coefficient and channel capacity loss.<br>General Secretariat of Education and Scientific Research Libya

The rapidly growing demand for UWB as high data rates wireless communications technology, since the Federal Communications Commission (FCC) allocated the bandwidth of UWB from 3.1GHz to 10.6 GHz. Antenna also plays an essential role in UWB system. However, there are some difficulties in designing UWB antenna as compared to narrowband antenna. The primary requirement of UWB antennas is be able to operate over frequencies released by the FCC. Moreover, the satisfaction of radiation properties and good time domain performance over the entire frequency range are also necessary. In this thesis, designing and analysing printed crescent shape monopole antenna, Planar Inverted F-L Antenna (PIFLA) and Planar Inverted FF Antenna (PIFFA) are focused. A Planar Inverted FF Antenna (PIFFA) can be created to reduce the potential for interference between a UWB system and other communications protocols by using spiral slot. The antennas exhibits broadside directional pattern. The performances such as return loss, radiation pattern and current distribution of the UWB antennas are extensively investigated and carried out. All the results have been demonstrated using simulation and experimentally whereby all results satisfy the performance under - 10dB point in the bandwidth of UWB. In addition the miniaturization of MIMO/diversity Planar Inverted-F antenna (PIFA) which is suitable for pattern diversity in UWB applications is presented. This antenna assembly is formed by two identical PIFAs, a T-shaped decoupling structure which connects the two PIFAs and a finite ground plane with a total compact envelope dimension of 50 x 90 x 7.5mm³. The radiation performance of the proposed MIMO antenna was quite encouraging and provided an acceptable agreement between the computed and measured envelope correlation coefficient and channel capacity loss.

This thesis investigates the radiation characteristics of a semi-populated cellular mobile handset that uses two Printed Inverted-F Antennas (PIFAs). The investigation is carried out at three different frequencies; the LTE Band 13 (746-786 MHz), GSM-900 (890-960 MHz) and GSM-1800 (1710-1880 MHz). The mobile handset is populated with the components that affect the antenna properties the most, a battery and an LCD screen, to make the investigated model more realistic. A methodology is first presented to design the PIFAs in the presence of other components on the board. Using the outlined method, antennas for three semi-populated mobile handsets are designed to satisfy specific operational performance targets. The two PIFAs fabricated for the GSM-1800 handset have a maximum gain of 2.98 dB and 3.18 dB, reflection coefficients of below -9 dB and a maximum mutual coupling of -7.9 dB. The two fabricated PIFAs of the GSM-900 handset exhibit a maximum gain of -0.02 dB and -3 dB, reflection coefficients of below -10.5 dB and a maximum mutual coupling of -6 dB. The measured gain values for the two PIFAs of LTE-Band 13 handset prototype are 0.19 dB and -11 dB, while both achieving reflection coefficients of below -4.5 dB and a maximum mutual coupling of -11 dB. The three designs all indicate that the presence of the components on the handset degrade radiation performance. The three handsets nevertheless are well designed to meet all the performance targets except for the mutual coupling. Fullwave pointing vector simulations are conducted to investigate the coupling between the PIFAs showing that the power transfer between the GSM-1800 and GSM-900 PIFAs mostly takes place through radiation. The power coupled between the LTE-Band 13 handset antennas on the other hand is majorly through the handset's structure and substrate-bound modes.A survey of different mutual coupling reduction techniques is presented. A method that targets coupling through space-waves, i.e., the use of a parasitic radiator, is applied in this work to the GSM-1800 and GSM-900 handsets. The parasitic radiator succeeds in bringing the maximum coupling between the GSM-1800 handset antennas to below -18 dB and below -17.5 dB for the GSM-900 handset antennas. The mutual coupling between the LTE-Band 13 handset antennas is reduced by using an Electromagnetic Band-Gap structure, which successfully decreases it to below -12.2 dB.<br>Cette thèse analyse les caractéristiques des radiations d'un téléphone mobile cellulaire semi-peuplé utilisant deux antennes imprimées en F-inversé (PIFAs). L'enquête est réalisée à trois fréquences différentes; la bande LTE 13 (746-786 MHz), GSM-900 (890-960 MHz) et GSM-1800 (1710-1880 MHz). Le téléphone mobile est constitué d'une batterie et d'un écran LCD dont le but est de rendre le modèle étudié plus réaliste. Le modèle utilisé vise d'abord à représenter la conception des PIFAs et ceci avec d'autres composants. Par référence a la méthode de conception qui a été décrite, les antennes de trois semi-peuplées téléphones mobiles sont conçus pour satisfaire des objectifs spécifiques de performance opérationnelle. Les deux PIFAs fabriques pour les mobiles GSM-1800 ont un gain maximal de 2.98 dB and 3.18 dB, coefficients de réflexion inférieur à -9 dB et un couplage maximal mutuel des -7.9 dB. De plus, les deux PIFAs fabriques pour les mobiles GSM-900 ont un gain maximal de -0.02 dB and -3 dB, coefficients de réflexion ci-dessous -10.5 dB et un couplage maximal mutuel de -6 dB. Enfin, les deux PIFAs fabriques pour les mobiles LTE-Band 13 atteignent un gain maximal de 0.19 dB and -11 dB, un coefficient de réflexion ci-dessous -4.5 dB et un couplage maximal mutuel de -11 dB. Les trois modèles indiquent que la présence d'autres composants provoquent la dégradation des performances des radiations. Néanmoins, les trois mobiles répondent à toutes les caractéristiques de rendement sauf celui pour le couplage mutuel. Des simulation utilisant des vecteurs pleine-onde pointant sont effectuées pour investiguer le couplage entre les PIFAs. Les simulations indiquent que le tranfert de la puissance couplée entre les antennes pour les mobiles GSM-1800 et GSM-900 se déroule en dehors du mobile. Alors que la puissance couplée entre les antennes de téléphones LTE-bande 13 se fait à travers la structure et le substrat-lié du mobile. Une récapitulation des différentes techniques de réduction des couplages mutuels a été présentée. Une méthode visant les ondes spatiales i.e., utilisation d'un radiateur parasite, est appliquée aux mobiles GSM 1800 et GSM--900. Le radiateur parasite parvient à rendre le couplage maximal, pour les antennes GSM-1800, au-dessous de -18 dB et pour les antennes GSM-900 au-dessous de -17,5 dB.Le couplage mutuel de la LT-bande 13 est réduite en utilisant une structure de bande-interdite électromagnétique, qui apporte avec succès le couplage maximal mutuel pour les antennes à moins de -12,2 dB.En conclusion, la structure PIFA est une option viable pour une utilisation d'un téléphone mobile pour les bandes de fréquences d'une enquête, et ceci en appliquant les techniques de réduction mutuelles de couplage appropriées.

yes<br>A frequency tunable planar inverted F antenna (PIFA) is presented for use in the following bands: DCS, PCS, and UMTS. Initially, the tuning was achieved by placing a lumped capacitor, with values in the range of 1.5 to 4 pF, along the slot of the radiator. The final tuning circuit uses a varactor diode, and discrete lumped elements are fully integrated with the antenna. The antenna prototype is tunable over from 1850 MHz to 2200 MHz, with an associated volume of 21×13.5×5 mm3, making it suitable for potential integration in a commercial handset or mobile user terminal.

碩士<br>國立臺灣海洋大學<br>電機工程學系<br>102<br>The purpose of this thesis is to propose an open slot antenna and PIFA for WLAN applications. Both structure are simple and easy to make. it conformed to the requests of many consumer products and communication facilities that concerned with easy manufacture ,light weight, low cost and small size. The open slot antenna is use microstrip line to design, the antenna size is (30#westeur024#35#westeur024#0.8mm^3)，substrate thickness is 0.8mm of double-sided FR4。Front of the antenna has a rectangular metal(7#westeur024#6mm^2)，and connected to the input impedance of 50 ohm microstrip line. The back of the antenna has L-shaped and U-shaped slot，them resonate high and low frequency respectively. First use the L-shaped slot to obtained low frequency, then in the less sensitive of low frequencies and a built-in inverted U- slot to obtained the high frequency, Final change the size and shape of the slot to complete the resonant frequencies, Without increasing the antenna size to operating band of WLAN applications 2.4/5.2/5.8GHz. A typical PIFA include a rectangular metal sheet, ground plane and short circuit plate connect edge of the rectangular flat metal sheet shorter side. The proposed PIFA is use coaxial feed mechanism to design. The inner conductor of the coaxial line is connected to the radiator plane over the substrate, and through the dielectric substrate, and the outer conductor of the coaxial line connected to ground plane, and use short circuiting contactor instead of short circuit plate. By changing the size and shape of the radiator plane，or changing position of feed and short circuiting contactor to reach frequency at 2.4GHz and 5 ~ 6GHz dual-band planar inverted-F antenna's. Finally, simulate Return loss is similar to measure of the PIFA and open slot antenna. Although it is shift of frequency but is not significantly affected, the bandwidth still includes frequency of WLAN. In conclusion, the simulate and measure are not exactly the same, but the trend is close to measure of the characteristic.

碩士<br>國立臺北科技大學<br>電子工程系<br>107<br>With the rapid development of wireless communication, the demand for mobile communication devices based on multi-band operation is increasing, and the development of multi-band antennas is promoted. Planar inverted-F antenna (PIFA) has excellent performances such as small size, light weight, high efficiency and low cost, which is widely used in portable devices like mobile phones; in addition, PIFAs are also commonly applied in RFID, MIMO and wireless communication system. However, most of conventional PIFA antennas can only be operated in a single frequency band. This is the main disadvantage of the antenna, which is also the purpose of this research. In this thesis, the high-frequency structure simulator（HFSS） is used to simulate the PIFA antenna that can be worked in multi-band. Moreover, the current distribution can be observed and analyzed. The multi-band PIFA antenna is designed by the use of parasitic and slot elements, which are pattern measured in anechoic chamber and its return loss is measured by using the network analyzer. The antenna consists of main patch with parasitic element and ground plane. The volume is 40 x 31 x 0.8 〖mm〗^3 and 60 x 40 x 1.6 〖mm〗^3, respectively. The operating frequency is optimized from a single band to multi-band, which can improve the practical disadvantage of the conventional PIFA antenna effectively.