Dual-band Planar inverted-F Antenna Research Articles

Key Technology of Mixed Matching Circuit for Miniaturizing Dual-Band Antenna

A mixed matching circuit for miniaturizing dual-band antenna is introduced and verified in this paper. According to the dual-band allocations on the Smith chart, two L-shaped matching circuit for miniaturization are cascaded to interpret the theory of operation. A matching circuit formula is deduced based on a bidirectional matching track from a certain position to the origin point on the Smith chart. Furthermore, a dual-band antenna is taken as an example to illustrate the performance of the novel matching approach for miniaturization. The occupation of a dual-band antenna can be reduced by a quarter at the simultaneous operational frequencies of 2.4 and 5.8 GHz. Finally, a dual-band planar inverted-F antenna (PIFA) is fabricated and measured. The experimental results have a good agreement with those in the simulator.

Design of a Dual Band On and Off-Body Antenna for Medical Applications

Design of a dual-band Planar Inverted-F Antenna (PIFA) for on-body and off-body communications implementable in medical applications is presented in this paper. Both free-space and on-body performance parameters of this antenna are shown and examined through the simulation process using CST software. This planer inverted F antenna works at ISM band (2.45 GHz, on-body) and HiperLAN band (5.2 GHz, off-body) simultaneously. This proposed PIFA radiates at the ISM frequency band, dual-band is achieved due to the double F slits and radiates at the HiperLAN frequency band as well. Performance parameters such as return loss, bandwidth, radiation pattern, and efficiency on free space of this antenna are examined first. Then the on-body performance parameters of this dual-band PIFA have also been tested on some close proximities such as 4mm, 8mm, and 16mm distance from a modified 3-layers human body model. Comparison and analysis between free space results and on-body results are also shown in this paper. As the proposed antenna reveals significant on-body performances at both ISM and HiperLAN bands, it can be said that this antenna will be suitable to be used in different medical applications.

Design Implantable Antennas with Human Body Effect

Implantable antenna devices have made great progress for healthcare services. Amongst the overall components of the implantable device, the antenna is the most important component that exists; it used to transmit the biological data wirelessly from inside the human body tissues to an external receiver. However, the human body tissues’ surrounding the antenna decrease the performance of the radiation antenna device, change its characteristics and absorbs most of its radiation. It also limits the size of the implantable device and its battery. Therefore, the design of the implanted antenna inside the human body requires many challenges while meeting many contradictory design parameters at the same time. Therefore, in this research, we mainly focused our spotlight on investigating and designing new antenna structures with robust performance against the human body tissue effect. In this research work, we presented two designs of a dual-band microstrip patch implantable antenna to operate ((401-406 MHz) Medical Device Radio-Communications (MedRadio), 433MHZ 2.45 GHz Industrial, Scientific and Medical (ISM) bands, respectively. This is to satisfy the requirements of data transfer, power saving and wireless power transfer. The first design in this paper is a new shape of microstrip patch implantable antennas with meandered serpentine slot, with a single feed point. This shape of design allows us to increase the length of the current path in order to decrease the antenna size and covers MICS and ISM bands with new dimensions of (31 x 25 x 1.63) mm, the measured frequencies range we obtained it’s from 378MHz to 450 MHz (17.3%) at the lower band and from 2.46 to 2.68 GHz (8.56%) at the upper band for 11 less than -10 dB. The second simulated design is a compact dual-band Planar Inverted-F Antenna (PIFA) with Open-End Slots on ground with dimensions of (19.8x19.4x1.27) mm the measured frequencies from 325MHz to 407MHzrange at the lower band and from 2.412GHz to 2.482GHz for PIFA antenna, the designs of both antennae constructed and measured using CST and HFSS simulation and measurement setup. We also explained and demonstrated the performance of these antenna designs and the effect of human body tissue on antenna parameters, based on the reflection coefficient in normal and bent conditions.

Integrated Millimeter-Wave Wideband End-Fire 5G Beam Steerable Array and Low-Frequency 4G LTE Antenna in Mobile Terminals

In this paper, a novel technique of collocating a millimeter-wave end-fire 5G beam steerable array antenna with a low-frequency planar inverted-F antenna (PIFA) is presented. In this technique, the low-frequency antenna can be transparent by using some grating strips between the low- and high-frequency antennas. A quad-element mm-wave array with end-fire radiation patterns operating in 22–31 GHz is integrated with a dual-band low-frequency PIFA in a mobile terminal. The novelty of this paper is the collocation of a high-frequency end-fire 5G antenna array with an old-generation low-frequency antenna, such as 4G in small space in the mobile terminal, without interfering with the radiation pattern and impedance matching of both low- and high-frequency antennas. The proposed 5G antenna covers 22–31 GHz and can scan ±50° with the scan loss of better than 3 dB. The coverage efficiency of the proposed mm-wave 5G antenna is better than 50% and 80% for a minimum gain of 4 and 0 dBi in 22–31 GHz, respectively. The gain of the high-frequency antenna array is better than 9.5 dBi at 28 GHz. The low-frequency antenna covers some practical 4G LTE bands from 740–960 MHz and 1.7–2.2 GHz bands. The measured results in both low and high frequencies agree well with the simulations.

Optimization of Efficient Dual Band PIFA System for MIMO Half-Duplex 4G/LTE and Full-Duplex 5G Communications

In this paper, a two efficient Planar Inverted-F Antenna (PIFA) system for dual-band functionality on fourth-generation (4G) band (2.5-2.7 GHz) and future fifth-generation (5G) band (3.4-3.8 GHz) is presented. During the optimization process, in order to obtain an efficient system, particular attention has been paid to the antenna system efficiency as well as the isolation between the antennas. Thus, the influence of the antenna slot design used to achieve a dual-band behavior on the antenna efficiency has been particularly studied. Moreover, the antenna positions on the Printed Circuit Board (PCB) have been chosen thanks to the use of characteristic mode analysis to obtain high isolation levels in both bands. The final system is optimized for Multiple Input Multiple Output Half Duplex (MIMO HD) 4G communications and Tx/Rx Full-Duplex (FD) 5G communications. A prototype with 140 mm × 70 mm ground plane was simulated, fabricated and measured. A high isolation level between the two ports of the PIFA elements, better than 35 dB in 5G band and 20 dB in 4G band in simulation and measurement that were done in free space, is obtained. Additionally, the most important diversity metrics are computed to evaluate the potential of this two-antenna system for diversity applications.

Dual-Band Platform-Free PIFA for 5G MIMO Application of Mobile Devices

A dual-band platform-free antenna is proposed for the 5G multiple-input multiple-output (MIMO) application of mobile devices. The antenna is formed by adding a vertical metallic patch to the planar inverted-F antenna (PIFA) and setting another PIFA to feed the antenna by coupling. The vertical patch can effectively suppress the fringe currents on the ground plane, which makes the antenna electromagnetic compatible on different working platforms, e.g., the antenna is not affected by other components inside the real device and vice versa. The coupling feed helps to realize a dual-band operation and reduces the length of antenna to around $\lambda $ /8, which makes the antenna more applicable in smartphones. As a design example, a handset MIMO antenna with eight elements is fabricated and measured. Furthermore, the throughput achieved by the antenna in an indoor environment is tested with an MIMO system developed by the Communication Laboratory of Huawei Corporation. The effect of one hand on the MIMO performance is also studied.

A compact planar inverted-F antenna with U-shaped strip for all-metal-shell handset application

A compact dual-band planar inverted-F antenna (PIFA) with U-shaped strip is proposed in this work for all-metal-shell mobile telephone application. As metal-shell handsets are getting more and more popular nowadays, it raises a big challenge in antenna design as the metal-shell associated with surrounding electronic components like front-back-cameras and telephone receiver would affect the antenna performance. This work provides an optional solution to alleviate this problem, where the metal shell of the handset and a U-shaped strip are utilized as part of the antenna. The proposed antenna is able to generate radiation at 2.4 GHz for Wi-Fi application with the help of the metal shell while using the U-shaped strip can achieve a resonance at 1.575 GHz for GPS application. A prototype has been fabricated to verify the radiation performance in a practical handset test environment.

Compact Dual-Band Decoupling Structure for Improving Mutual Coupling of Closely Placed PIFAs

In this letter, a dual-band isolation enhancement technique for two closely located dual-band planar inverted-F antennas (PIFAs) is proposed using a compact planar spiral line (PSL) structure. The decoupling structure has the dimensions of less than 0.15λ × 0.1λ and can be flexibly applied to various practical multiple-input multiple–output systems. By employing this structure, two PIFAs (with port distance of 0.1λ) can achieve high isolation better than 20.3 and 26.7 dB within the lower band (2.4–2.483 GHz) and higher band (5.25–5.9 GHz), respectively. Meanwhile, the decoupling mechanism and design requirement of PSL are discussed. Influences of the proposed PSL to the efficiency, gain, and radiation pattern of PIFAs were also studied. Good agreement between the simulated results and measured results is obtained.

Dual Band PIFA for WLAN and WiMAX MIMO Systems for Mobile Handsets

A compact planar inverted-F antenna (PIFA) dual band two-unit multiple-input multiple-output (MIMO) antenna system withhigh isolation is developed. The proposed MIMO antenna that consists of two PIFA elements has the advantage of compactstructure and multi-band for mobile device. The proposed antenna can cover the frequency range from 2.36GHz to 2.52GHz and 5.05GHz to 5.98GHz, therefore, it includes applications: High Performance radio Local Area Network/2 (5.2GHz/5.6GHz),Wireless Local Area Network (2.4GHz/5.2GHz/5.8GHz), Bluetooth (2.4GHz) and Worldwide Interoperability for MicrowaveAccess (5.5GHz). By integrating a +shaped slots in the ground plane, we can increase the isolation between elements of theproposed antenna. The maximum gain of the proposed MIMO-antenna is 10.07dB at 2.44GHz and 9.97dB at 5.55GHz.

Metamaterial-Embedded Low SAR PIFA for Cellular Phone.

A metamaterial-embedded planar inverted-F antenna (PIFA) is proposed in this study for cellular phone applications. A dual-band PIFA is designed to operate both GSM 900 MHz and DCS 1800 MHz. The ground plane of a conventional PIFA is modified using a planar one-dimensional metamaterial array. The investigation is performed using the Finite Integration Technique (FIT) of CST Microwave Studio. The performance of the developed antenna was measured in an anechoic chamber. The specific absorption rate (SAR) values are calculated considering two different holding positions: cheek and tilt. The SAR values are measured using COMOSAR measurement system. Good agreement is observed between the simulated and measured data. The results indicate that the proposed metamaterial-embedded antenna produces significantly lower SAR in the human head compared to the conventional PIFA. Moreover, the modified antenna substrate leads to slight improvement of the antenna performances.

Design and analysis of metamaterial inspired low SAR PIFA for mobile phone

In this paper, a metamaterial embedded planar inverted-F antenna (PIFA) is proposed for cellular phone. A dual band PIFA is designed to operate both GSM 900 MHz and DCS 1800 MHz. The ground plane of conventional PIFA is modified using a double negati

Design of a novel dual: band planar inverted F - antenna for mobile radio applications

The design of a novel compact dual band PIFA (Planar Inverted F-Antenna) as an embedded antenna is reported in this paper for mobile radio applications. The new shorted planar antenna is realized using copper sheet of thickness 1mm and air as the dielectric substrate. The radiating patch consists of a branch line slit to reduce the size of the antenna having a ground size of 36 x 80 mm2. It can be used in internal mobile antennas for applications in GSM band, GCV (1.85 - 1.99GHz), PCS - 1900, IMT-2000 and UMTS 2100 networks. The simulations are done using the Ansoft High Frequency Structure Simulator (HFSS) software tool. The two operating frequency ranges obtained have good matching and radiation characteristics. The simulated results are well supported by measured results of the prototype of the antenna fabricated.

Low-Profile Folded-Coupling Planar Inverted-F Antenna for 2.4/5 GHz WLAN Communications

A dual-band folded-coupling planar inverted-F antenna (FC-PIFA) is presented in this paper. By using the folded-coupling technique, the proposed antenna provides two distinct impedance bandwidths of 159 MHz (about 6.5% centered at 2.45 GHz) and 1512 MHz (about 27.5% centered at 5.5 GHz), which cover the required bandwidths for the 2.4/5 GHz wireless local area network (WLAN) communications. Moreover, the antenna shows a low profile of 5 mm and a small length of 20.5 mm in radiating area, making it easy to be installed in the casing of wireless handheld devices and laptops. Details of the design procedures and experimental results are discussed.

Linearly polarised planar inverted F‐antenna for Global Positioning System and Worldwide Interoperability for Microwave Access applications

A compact dual-band planar inverted-F antenna in conjunction with an inverted L-shaped parasitic and reduced ground-plane structure working in the GPS (Global Positioning System) band (1565–1585 MHz) and Worldwide Interoperability for Microwave Access band (3300–3800 MHz) is presented. The antenna meets the strict space requirements of the portable devices and the final design fits a volume of 100 × 24 × 9.7 mm3 (L × W × H). It is composed of a series of branches, properly dimensioned and separated to generate the resonances at the desired frequencies. The antenna is fabricated using a 0.2 mm thick copper foil. The linearly polarised antenna exhibits good impedance matching performance, wide beam radiation pattern and high gain. Also, carrier-to-noise ratios for three different satellite locations, that is, 5°, 50° and 90° elevation are 47.58, 50.49 and 45.86 dB/Hz, respectively, at the centre frequency (1575 MHz) of GPS L1 band, which is well within the maximum allowable limit (50.5 dB/Hz) at room temperature.

Miniaturization of Dual-Band PIFA for Wireless LAN Communication

In this letter, a simple method for reducing the size of a dual-band planar inverted-F antenna (PIFA) is described. This method is based on a coupling capacitor connected in parallel to the PIFA feed conductor. The proposed antenna occupies a small ground clearance of 10 mm×5 mm and is able to provide −10-dB impedance bandwidths of 120 MHz and 760 MHz for 2.45-GHz and 5.5-GHz wireless local area network applications, respectively. The measured antenna efficiencies are 71.8% and 73.6%, averaged over the 2.45-GHz and 5.5-GHz frequency bands, respectively.

Miniaturization of Dual-Band PIFA for Wireless LAN Communication

In this letter, a simple method for reducing the size of a dual-band planar inverted-F antenna (PIFA) is described. This method is based on a coupling capacitor connected in parallel to the PIFA feed conductor. The proposed antenna occupies a small ground clearance of 10 mm×5 mm and is able to provide −10-dB impedance bandwidths of 120 MHz and 760 MHz for 2.45-GHz and 5.5-GHz wireless local area network applications, respectively. The measured antenna efficiencies are 71.8% and 73.6%, averaged over the 2.45-GHz and 5.5-GHz frequency bands, respectively.

Dual-Band Integrated Antennas for DVB-T Receivers

An overview on compact Planar Inverted-F Antennas (PIFAs) that are suitable for monitor-equipped devices is presented. In particular, high efficiency PIFAs (without any dielectric layer) with a percentage bandwidth (%BW) greater than 59% (470–862 MHz DVB-T band) are considered. In this context, two PIFA configurations are reviewed, where a dual-band feature has been obtained, in the 3300–3800 MHz (14% percentage bandwidth) WiMAX and 2400–2484 MHz (2.7% percentage bandwidth) WLAN IEEE 802.11b,g frequency bands, respectively, to also guarantee web access to on-demand services. The two PIFAs fill an overall volume of mm3and mm3, respectively. They are composed of a series of branches, properly dimensioned and separated to generate the required resonances. Finally, to show the extreme flexibility of the previous two configurations, a novel dual-band L-shape PIFA has been designed. A reflection coefficient less than −6 dB and −10 dB and an antenna gain of around 2 dBi and 6.3 dBi have been obtained in the 470–862 MHz DVB-T band and the 2400–2484 MHz WLAN band, respectively. The L-shape PIFA prototype can be obtained by properly cutting and folding a single metal sheet, thus resulting in a relatively low-cost and mechanically robust antenna configuration.

A Novel Methodology to Design Miniaturized Regular Planar Inverted-F Antennas Based on Parametric Simulations

This paper describes a novel methodology to design PIFA (Planar Inverted-F Antenna) antennas based on parametric simulations. The parameters considered in the parametric design are ground plan dimensions, height of radiating plate, feeding point position, shorting plate width and position. The choice of the parameters that must be varied independently or simultanously is important to design optimized antenna. The author studied two scenarios in precedent works [1,2]. He exposes here a third scenario of varing antenna parameters to design and simulate by HFSS (High Frequency Simulator Structure) simulator a probe-fed dual band PIFA for the use in GSM 850 band (824 MHz - 894 MHz) and PCS 1900 band (1850 MHz - 1990 MHz). The author compares the three scenarios and establishes a novel methodology to design optimized and miniaturized antennas mounted on mobile handsets.

Multiple Frequency Band and High Isolation Mobile Device Antennas Using a Capacitive Slot

The performance characteristics of the capacitive slot, or a slot placed between the feed and ground connections, in a planar inverted-F antenna (PIFA) are comprehensively analyzed. The PIFA capacitive slot behavior is measured inside a two antenna system within a mobile phone where the first antenna is a multiple band PIFA and the second antenna is a higher frequency band PIFA directly overlapping with the first antenna higher frequency band. The dual band PIFA in this paper is designed to be resonant in the quad-band GSM+3 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</i> /4 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</i> , and the second PIFA is resonant in the 3G/4G frequency bands. The capacitive slot has three types of behaviors: affect the matching of existing frequency resonances, induce another frequency resonance, and improve the isolation between the two antennas. Together with optimal antenna ground and feed placement, the capacitive slot can act as a notched bandstop filter to decrease the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub> mutual coupling between the two antennas by over 20 dB and decrease the envelope correlation by almost one order of magnitude.

A Compact Dual-Band PIFA for DVB-T and WLAN Applications

A compact dual-band Planar Inverted-F Antenna (PIFA) working in both the DVB-T (Digital Video Broadcasting-Terrestrial) and the WLAN (Wireless Local Area Network) IEEE 802.11b,g frequency bands is presented. It is designed to be integrated in a monitor-equipped device, and exhibits reduced electrical size with respect to similar PIFA configurations. A reflection coefficient less than -6 dB and -10 dB was obtained in the 470-862 MHz (59% percentage bandwidth) DVB-T and the 2400-2484 MHz (2.7% percentage bandwidth) WLAN bands, respectively. An antenna gain of almost 3 dBi and 4.5 dBi, with more than 95% radiation efficiency, was obtained in the two frequency bands of interest. The PIFA fills an overall volume of 217 × 12 × 8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> and can be realized by a properly cut and fold single metal sheet. Measurements on prototypes have shown that the proposed layout is robust in terms of the impedance matching detuning that can be caused by the presence of metal parts nearby the antenna.