Planar inverted-F Antenna Research Articles

Reduction of Specific Absorption Rate using carbon foam inside enclosures

The interaction of a mobile antenna and a passenger is analyzed inside a metallic enclosure. The specific absorption rate (SAR) of the passenger in the elevator using a mobile phone is calculated. A standardized model of human head is filled with liquid that simulates the RF absorption characteristics. The non-uniform mesh technique in frequency domain is employed to obtain 1g SAR [Specific Absorption Rate] and other important parameters. The mobile phone is modeled as a quarter wavelength Planar Inverted F Antenna (PIFA), and it is of .01m from the head. PIFA is operated at frequencies of 900 and 1800MHz with transmitting power .3 W . It is observed that the values of SAR inside the metallic enclosure exceeds the RF safety limits. Therefore, this project proposes a novel method to reduce the SAR by using carbon foam which absorbs microwave radiation. Simulated results have evidenced the efficiency of the proposed technique of SAR reduction inside the enclosures.

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.

Dual band frequency tunable planar inverted‐F antenna for mobile handheld devices

A single feed, dual-band frequency tunable planar inverted-F antenna (PIFA) is presented for mobile handheld device applications. The proposed antenna is designed using the transmission line model. The dual-band frequency tunability is achieved by varying the capacitance of the varactor diode between 4.15 pF (0 V) and 0.72 pF (15 V). The measured impedance bandwidth of −6 dB is realized from 0.8 to 0.98 GHz for the lower band and 1.65 to 2.2 GHz for the higher band. The designed antenna provides the independent frequency tunability for both the bands without disturbing each other. The maximum antenna gain is estimated 2.64 dBi for the proposed PIFA. Also, it has a maximum efficiency of ~85% for the mobile handheld device. In addition, the proposed PIFA is investigated with SAM phantom model for head and hand, found to be within the acceptable SAR limit of 1.6 W/Kg.

Modelling of Mobile Electromagnetics Wave Effects on the Human Head

The effects on the heads of human of the electromagnetic waves produced by mobile antenna are presented in this paper. The interactions between electromagnetic energy and the human head are modelled using a COMSOL simulation and the distributions of the produced electric field and resultant temperature inside the human head are obtained. A planar Inverted-F antenna (PIFA) was adopted in this modelling. Three levels of transmitted power (0.6, 1, and 1.5 Watt) were applied in the simulation to determine any increases in temperature in the brain due to microwave radiation from the mobile antenna.

Design and Fabrication of a Planar Inverted-F Antenna (PIFA) for LEO Satellite Application

The paper is mainly emphasizes on the microstrip patch antenna design for satellite applications. The specific objective of this study is to solve the research problem on finding the simple and compact design for small satellite application in real world. A new design of a Planar Inverted-F Antenna (PIFA) with the two height of 12mm and 10mm are proposed for low Earth orbit (LEO) applications in S band. The antenna is a single form antenna with the coaxial probe fed is used. CST Microwave Studio student version was used for the simulation of the antenna and matching design parameters. The antennas are obtained an efficient high return loss -18.426dB and -18.169dB at S11, the return loss bandwidth of 471MHz and 466MHz. The radiation pattern results are analyzed beam width angle 85.1° and 95.1°. Moreover, the peak directivity gain results 4.7dBi and 4.79dBi, the absolute E-filed radiation effect are also presented. The actual measurement results for S11 parameter of return loss -13.54dB and -14.2dB, return loss bandwidth of 510MHz and 425MHz are also fabricated with the comparison of simulation and fabrication process of PIFA antenna characteristics. The measurement of the return loss (S11) and return loss bandwidth were almost identical with the simulation.

Electrically Small Spiral PIFA for Deep Implantable Devices

In this paper, a miniaturized implantable circularly polarized spiral Planar Inverted-F Antenna (SPIFA) in the UHF (600-800 MHz) band is presented. This antenna is intended for deep implantable devices such as leadless pacemakers and deep brain stimulation (DBS), which facilitates the reception of RF power from an external transmitter. The antenna is electrically small, with a volume of π × 5 mm x 5 mm × 3.2 mm and a diameter of 0.022λ. The performance of the proposed antenna in terms of reflection coefficient, realized gain and axial ratio are assessed when accounting for the effects of operating in different types of human body tissues, different biocompatible materials and different thicknesses and depths of the implanted antenna. Finally, the antenna is prototyped and measured in free space, a phantom model, in a cow's fat and muscle tissues to validate the simulation results, indicating good agreements. A realized gain around -20 dBm is achieved when operating in 50 mm depth in cow's muscle tissue while having electrically very small dimensions compared to implantable antennas reported in the literature.

DGS based Planar Inverted F Antenna for Multiband Applications

As Long Term Evaluation systems have more benefits when compared to other network systems, it became more popular. Integrating a lower band with a higher by considering space as a constraint became a challenge for designers. A simple PIFA (Planar Inverted F Antenna) with DGS(Defective Ground structure) is suggested inmultiple band applications. The proposed antenna is designed using the CST Microwave Suite 2017. The design is for substrate having εrof 4.4(FR-4), (tan δ ) 0.02 as loss tangent with a thickness of 1.53mm is preferred for designing of this antenna and is etched directly upon the substrate.

Flexible EBG‐backed PIFA based on conductive textile and PDMS for wearable applications

AbstractA wearable planar inverted‐F antenna (PIFA) fed by the coplanar waveguide (CPW) and backed with an optimized electromagnetic bandgap (EBG) structure is presented. The antenna is made of conductive textile and polydimethylsiloxane (PDMS), which is a conformal and robust solution to wearable applications. The EBG unit cell is miniaturized according to the equivalent circuit model, and the cross‐polarization is suppressed due to its approximate 180° reflection phase in the orthogonal direction. The measured impedance bandwidth ranges from 2.30 to 2.65 GHz, which covers the 2.4 GHz Industrial Scientific Medical (ISM) band. The antenna keeps a high gain and efficiency above 70% under different conditions including being flat, bent, and close to the human body. The maximum SAR value is limited to 0.612 and 0.330 W/kg under 1 and 10 g standard, respectively. Therefore, the antenna is a promising candidate for wearable applications in various domains.

A Compact MIMO Planar Inverted-F Antenna

In this work, a compact MIMO antenna is designed as a planar inverted F-antenna (PIFA) which can be used for smallest smartphones. The proposed antenna will cover the GSM frequency range of 900MHz and 1800MHz. Those dual bands are attained with high gain up to 4.7dB. Simulation and experimental results have been presented.

Design and Implementation of a Tri-Band Miniaturized Planar Inverted-F Antenna with Double Resonator for GPS Application

In this paper, a new planar inverted-F antenna is presented for GNSS applications and the DCS band. The proposed antenna structure is based on capacitive slots that achieve multiband behavior. The antenna has two resonators of dimensions (31mm×17mm×0.35mm) and (20.5mm×17.5mm× 0.35mm), a ground plane (60mm×17.5mm×0.35mm) and 6.5mm height. A prototype was implemented and good agreement was noticed between the simulation and test results, indicating three resonant frequencies, namely 1.176GHz, 1.8GHz and 2.8GHz. Radiation characteristics and diversity performance of the proposed structure is presented with detail.

Design and Implementation of a Tri-Band Miniaturized Planar Inverted-F Antenna with Double Resonator for GPS Application

Design and Implementation of a Tri-Band Miniaturized Planar Inverted-F Antenna with Double Resonator for GPS Application

Wideband Circularly Polarized Planer Inverted-F Antenna using Reactive Impedance Surface

A wideband circularly polarized (CP) planar inverted-F antenna (PIFA) is proposed and designed using reactive impedance surface (RIS) for mobile communication. PIFA with RIS is used for CP radiation, size reduction and wideband of the proposed CP-PIFA. It is a different technique for improving the various performance parameters of the antenna, that is, narrow bandwidth, size reduction, and the axial ratio (AR). The structure of circular polarized PIFA is designed, analyzed, geometrically optimized, and implementation of the antenna to operate at 2.4 GHz WLAN bands. Finally, a proposed CP-PIFA is analyzed and simulated using full 3D electromagnetic high-frequency structure simulator (HFSS). The measured impedance bandwidth of designing an antenna (S11) 10-dB is 1399 MHz (1.542-2.943 GHz) 58.29\%, simulated 3-dB axial ratio bandwidth is 870 MHz (1.639-2.50 GHz) 36.25\%, measured voltage standing wave ratio (VSWR) is 1.02 and the realized gain is 8.1 dB for the 2.4 GHz WLAN bands.

A Dual-Band Implantable Rectenna for Wireless Data and Power Support at Sub-GHz Region

An arm-implantable rectenna, supported by a compact planar inverted F-antenna (PIFA) and a rectifier, is proposed for wireless data telemetry and power transfer in the Medical Device Radiocommunications Service (401–406 MHz) and industrial, scientific, and medical (ISM) (902.8–928 MHz) bands. The rectifier is integrated into the system by using the antenna’s ground plane delivering, thus, a robust solution for the implanted devices. Each development stage is theoretically analyzed first and then experimentally tested. The antenna size is $16 \times 14 \times 1.27$ mm3. The slit/slot loading techniques applied onto the radiator offer the antenna size reduction and the dual-band operation. PIFA’s resonance stability is shown and its radiation and safety responses are addressed. Further, an arm-attached matching layer (ML) is proposed to enhance the wireless power link. Then, an analysis of rectifier circuits is conducted in order to obtain optimum conversion efficiency at low input powers. By following an attentive design process, the final system (rectenna) is built and tested in whole; the measurements verify our approach.

A compact multi‐band multi‐input multi‐output antenna for 4G/5G and IoT devices using theory of characteristic modes

A compact four element multi-band multi-input multi-output (MIMO) antenna system for 4G/5G and IoT applications is presented in this paper. The proposed antenna is developed using the theory of characteristic modes helping in systematic design of MIMO antenna system. It consists of four L-shaped planar inverted-F antenna (PIFA) elements each operating at 3.5, 12.5, and 17 GHz bands with the bandwidth of 359 MHz, 1 GHz, and more than 3.7 GHz, respectively. The proposed antenna system is suitable for both 4G/5G and internet of things devices as it shows the satisfactory MIMO system performance. Good isolation characteristics are observed by implementing complimentary Metamaterial structure on the ground plane resulting in isolation level lower than −21 dB between the antenna elements. The proposed antenna is fabricated and experimental results are also presented and discussed.

Isolation improvement of a two‐port PIFA for MIMO using a planar EBG ground

AbstractIn this article, the mutual coupling reduction of a two‐port planar inverted‐F antenna (PIFA) using a planar electromagnetic bandgap (EBG) structure is presented and investigated for multiple input multiple output/diversity applications. The planar EBG structure is designed for etching on the ground plane of the device. The EBG and the antenna design parameters are identified and the frequency scalability of the design is illustrated by showing two separate designs at 2.45 and 3.50 GHz. The optimized 2.45 GHz design demonstrates 25 dB more coupling reduction compared to the state of the art PIFA with a slot on the ground. Analyses of efficiency and effective diversity gain are also performed which show excellent performance.

Performance Analysis of Antennas in Structural Health Monitoring

Antennas with good performance are required for advancement in wireless structural health monitoring. Planar inverted-F antenna, dipole and microstrip patch antenna are used to study return loss (S11) at 2.4 GHz when they are embedded inside concrete pier. Antenna performance is studied in air and when it’s placed inside concrete. The return loss and the bandwidth along with other parameters are studied. It is observed concluded that the dipole antenna is more suitable when embedding antenna inside concrete of relative permittivity of 4.45.

Planar Antenna Covering Sub-6 GHZ for 5g Enabled Mobile Devices Worldwide

A miniaturized planar inverted F antenna (PIFA) for 4G/ 5G wireless technology is presented in this paper. It operates at frequency range 2.9 GHz to 4.9 GHz covering all the sub- 6 GHz frequency bands all over the world. The structure of PIFA is quite trouble-free and simple but the dimensions are quite minute. The patch is 11.3 mm x 8.3 mm. The antenna displays S11 equals to –37.9 dB at 3.9 GHz frequency. It seems really promising where simplicity is the concern for the 5G environment. The antenna is compatible with 4G environment and useful for 5G wireless technology.

Isolation Enhancement of Wideband Vehicular Antenna Array Using Fractal Decoupling Structure

Wideband vehicular planar inverted-F antenna (PIFA) array with high isolation by using a fractal structure is presented in this letter. The PIFA antenna elements are placed face to face, and the decoupling structure (DS) consisting of four fractal unit slots and a narrow line slot is inserted between elements to reduce the mutual coupling. The proposed structure is fabricated, and the suppression effect of mutual coupling is verified by both the simulation and measurement. Measured results show that the impedance bandwidth is from 3.02 to 3.96 GHz, which covers the 5G working frequency. An enhanced isolation of 8–32 dB in the frequency band of 3.17–4.15 GHz is obtained compared to without DS when the distance is only 0.17 λ 0 ( λ 0 is the free-space wavelength at the center frequency of 3.5 GHz) between two PIFA elements.

Miniaturized Dual Band Antennas for Intra-Oral Tongue Drive System in the ISM Bands 433 MHz and 915 MHz: Design, Safety, and Link Budget Considerations

An intraoral tongue drive system (iTDS) is an assistive technology that enables paralyzed people to improve their lifestyle by allowing them to navigate their wheelchairs and access computers using tongue gestures. In this paper, we present two dual-band antennas: a meandered dipole antenna and a meandered planar inverted-F antenna (PIFA). We designed the proposed antennas to operate at industrial, scientific, and medical (ISM) bands 433 and 915 MHz to mitigate the external interference issue, which can severely affect frequency bands. Our proposed antenna footprints are 17.25 × 8 × 0.635 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> and 42 × 10 × 0.635 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> for the PIFA and dipole antenna, respectively. Initially, we designed and analyzed the proposed antennas in multilayer mouth models. The performances of the antennas were validated in a realistic human head phantom. We analyzed the performances of the antennas in terms of the reflection coefficient, gain, efficiency, bandwidth, and link budget for wireless communication in four scenarios. Additionally, to address safety concerns, we calculated the specific absorption rates (SARs) for both antennas and found them to be safe according to the IEEE C95.1.2005 guideline. Finally, we measured the reflection coefficient in the more realistic environment of a 26 year-old subject's mouth. The radiation pattern was measured in a 3-D head model and minced pork muscle, which approximated the open and closed mouth scenarios, respectively. The measurement results were in reasonable agreement with the simulation results.

Super Ultrawideband Planar Inverted F Antenna on Paper based Substrate with Low SAR

In this paper, a super ultrawide band planar inverted F antenna (PIFA) has been proposed for wearable applications on a low cost, ecofriendly paper-based substrate. This work is a first and important step towards the progression of conformal flexible antennas for a body area network. The proposed antenna has measured impedance bandwidth of 10.6 GHz, which covers almost all the bands of a wireless body area network i.e. GSM (880-960 MHz), GPS (1565-1585 MHz), DCS (1710-1880 MHz), PCS (1850-1990 MHz), UMTS (1920-2170 MHz), ISM (2.4-2.4835 GHz), WiMAX (3.3-3.8 GHz), HIPERLAN (5.15-5.35 GHz), WLAN (5.725-5.850 GHz) and UWB (3.1-10.6 GHz). Initially, the electrical characteristics of paper are extracted using Cavity Resonator and Transmission line method and then used for the design and fabrication of the proposed antenna. The measured results are in good agreement with the simulated results. This paper also focuses on analysis of the effect of electromagnetic absorption in terms of specific absorption rate for a human arm with frequency exposure at 0.9 GHz, 1.5 GHz, 1.8 GHz, 3.5 GHz, 2.45 GHz, 5.2 GHz and 5.8 GHz and is found to be within the recommended limit by FCC.