Compact Planar inverted-F Antenna Research Articles

A Compact Broadband Planar Inverted-F Antenna with Dual-Resonant Modes

In this paper, a compact broadband planar inverted-F antenna (PIFA) with dual-resonant modes (TM1/2,2 and TM3/2,0) is proposed for 5G applications. By loading a pair of horizontal slots on the patch, the TM3/2,0 mode can be shifted downward and combined with the TM1/2,2 mode, leading to a dual-mode operation. Meanwhile, another pair of slots, which are orthogonal to the previous pair, is introduced to improve the impedance matching of the antenna. Moreover, the substrate with a high dielectric constant is used in this design to achieve a compact antenna size. In order to verify the principle and the design method, an antenna prototype was fabricated and measured. Experimental results show that the PIFA has a good performance with a −10 dB impedance bandwidth of 14.5% (3.17–3.67 GHz), a peak gain of 6.23 dBi, a low cross-polarization level of −17.3 dB, and a compact size of 0.45 × 0.26 × 0.03 λ013 (λ01 is the free-space wavelength at 3.5 GHz). The antenna is predicted to be suitable for 5G terminal applications.

Compact MIMO Systems Utilizing a Pixelated Surface: Capacity Maximization

Compact MIMO systems often suffer from degraded channel capacity due to spatial correlation. To overcome this issue, we propose a formulation for the channel capacity of a compact MIMO system that directly links it to the geometry of a pixelated surface embedded into the MIMO system. This formulation allows us to maximize the channel capacity of the MIMO system and straightforwardly obtain the optimum geometry for the pixelated surface that reduces spatial correlation. The key step in obtaining the formulation is to link the pixelated surface geometry to an impedance matrix that allows us to obtain an expression for the systems channel capacity. The formulation is general and can be applied to a wide variety of MIMO antenna systems and geometries. To demonstrate the versatility of the approach, we include a design for a compact 4-port planar inverted-F antenna (PIFA) array integrated with a pixelated surface. Simulations and experiments are provided to evaluate the performance of the compact MIMO system with and without optimization of the surface. It is shown that optimizing the geometry of the pixelated surface can increase channel capacity by 13% and energy efficiency by 19.9% compared to the system without optimization. The importance of the approach is that it provides a link between communication and electromagnetic formulations of MIMO antenna systems.

Compact Co-polarized PIFAs for Full-Duplex Application Based on CM/DM Cancellation Theory

In this article, a compact co-polarized decoupled antenna for full-duplex application working at 1.71 GHz is proposed. The antenna is composed of two back-to-back air-dielectric planar inverted-F antennas (PIFAs) with zero edge-to-edge distance. The whole system is included in a compact volume of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.45\lambda _{\mathrm {\mathbf {0}}} \times 0.45\lambda _{\mathbf {0}} \times 0.02\lambda _{\mathbf {0}}$ </tex-math></inline-formula> . The proposed antenna is designed based on the common mode (CM)/differential mode (DM) cancellation theory and its design guideline is illustrated in detail. Isolation maximum of 42 dB, broadside gain of 6.7 dB, and efficiency of 90% have been achieved in the proposed structure. There is a 1.9 dB gain difference between the broadside gain and the maximum gain. The proposed antenna shows its potentials in the radio frequency front-end incorporate design.

Compact Planar Inverted-F Antenna for MicroSats Omnidirectional Communications

In this letter, a planar inverted-F antenna (PIFA) working at 401.8 MHz is optimized for microsatellites (MicroSats) omnidirectional communication and omnidirectional communication is achieved by antenna layout optimization. Some parameters of the antenna are analyzed for investigating the influences to the resonant frequency and the gain. The PIFA occupies a small volume of 85 × 85 × 31 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , which is 0.011λ × 0.011λ × 0.004λ and has a maximum gain of 5.37 dBi after optimized. An omnidirectional, highly isolated dual-antenna communication satellite receiving system is realized by layout optimization simulation analysis. The effectiveness of the antenna and the layout optimization is verified by comparison between simulation and experimental results. The antenna has potential applications in MicroSats omnidirectional communications as the antenna has a small size and it can be quickly redesigned and manufactured.

Permittivity-Customizable Ceramic-Doped Silicone Substrates Shaped With 3-D-Printed Molds to Design Flexible and Conformal Antennas

3-D-Printing in antenna design is a recent research branch which is attracting academic and industrial interest. Nevertheless, despite the advantages in terms of antenna customizability, common filaments exhibit limitations in some contexts where platform tolerability, flexibility, and compactness are simultaneously required. Indeed, other than a rather low permittivity of commercial 3-D-printable materials, when flexibility is required, also significant loss tangent values must be accounted. To address this problem, a method to realize conformable flexible low-loss substrates with increased and customizable permittivity is proposed in this communication. It is based on the synthesis of ceramic-doped silicone structures shaped through 3-D-printed molds by using alumina and barium titanate as ceramic filler. Different substrates were firstly realized and characterized in terms of permittivity and loss tangent at different doping percentages. Then, a first validation on 2.4 GHz conformal patch antennas exploiting both third dimension and increased permittivity is presented. Finally, a wearable and compact bracelet-shaped UHF RFID planar inverted-F antenna (PIFA)-inspired flexible antenna is designed, tested when applied on the human body, and compared with a previously realized version 3-D-printed in polylactic acid. In spite of comparable performance, the novel device exhibits considerable size reduction and improved wearability, thus confirming the effectiveness of the proposed approach.

Compact reconfigurable PIFA antenna for wireless applications

This paper presents, new compact and multiband frequency reconfigurable planar inverted-F antenna (PIFA). The antenna is designed and optimized to cover mobile application devices like GPS, WLAN/Wi-Fi, WiMAX, 4G LTE, UWB, and satellite applications. The frequency reconfigurability is obtained by using only a single RF switch (PIN diode) for changing the operating frequency. The antenna dimensions are 45.6x39.6x1.6 mm 3 printed on an FR-4 epoxy substrate with relative dielectric constant er = 4.3, loss tangent tan (δ) = 0.002 and 50 Ω coaxial feed line. The proposed antenna has two patches connected by a single PIN diode. The antenna introduces nine resonant frequencies under (S11 ≤ -10 dB) which are: 0.980 GHz, 3.392 GHz, 3.924 GHz, 4.554 GHz, 5.82 GHz, 6.81 GHz, 7.305 GHz, 8 GHz and 8.105 GHz in the ON and OFF states of the PIN diode which are applicable to cover GSM900, WLAN/Wi-Fi, WiMAX, 4G LTE, UWB, and satellite systems. The obtained maximum simulated gain is 8.45 dB at 6.81 GHz. The lowest return loss is obtained to be -42 dB at 5.854 GHz. Detailed simulation and measurement results are explored and studied in this research. The CST software is used to simulate and optimize the proposed PIFA antenna. The proposed antenna has been fabricated and produced a good agreement with the simulation results.

Integrated planar inverted-F antenna on laptop computer’s hinge for 2.4/5.2/5.8-GHz WLAN operation

ABSTRACTA compact planar inverted-F antenna (PIFA) placed on one of the two hinges of a laptop computer is proposed for wireless local-area network (WLAN) operation. The aim of this design is to integrate the PIFA’s metal surroundings as part of the radiating structure. When the PIFA is fed, resonant modes in the hinge slot bounded by the two hinges, display ground plane, and keyboard ground plane can in turn be excited. Since the 200 × 5 mm2 slot is much larger than the 10 × 5 mm2 PIFA itself, the latter, although compact and structurally simple, can be made efficiently radiating with the help of the former. Measured efficiencies are all over 50% in the desired three WLAN bands

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.

Analysis and design of compact triple‐band meandered PIFA for 2.4/5.2/5.8 GHz WLAN

This study presents a novel compact (of volume 0.002 λg 3 ) triple-band planar inverted-F antenna (PIFA) for a wireless local area network (WLAN). The upper patch of the proposed antenna is meandered to resonate at WLAN bands and to make it compact. This meandering effect excites its second- and third-order modes along with the fundamental mode to cover all the three WLAN bands. A detailed analysis of the proposed PIFA is done using the theory of characteristic modes and the patch surface current distribution. The parametric study shows that two degrees of freedom are obtained to tune the all frequencies independently by varying the slots' parameters keeping the patch size fixed. In all the bands, it radiates at the broadside direction and provides a sufficient gain. Measured results are also presented here. The simulated and measured results are in agreement.

A Triband Planar Inverted-F Antenna with Quadratic Koch Fractal Shaped Slit Along with a Shorted Parasitic Strip

In this paper, a novel compact tri-band planar inverted-F antenna (PIFA) for mobile communication application is proposed. The antenna is capable to cover GSM 900 MHz, DCS 1.8 GHz and WLAN (IEEE 802.11b) 2.45 GHz bands. The proposed PIFA is composed of a quadratic Koch shape slit and a parasitic strip. The PIFA with the fractal shaped slit contributes to the first and second resonance while the shorted strip brings forth the third band. The impedance bandwidths of 84 MHz, 132 MHz and 81 MHz for GSM 900, DCS 1800 and WLAN (IEEE 802.11b) 2450, respectively are achieved. A realized gain of 2.44 dBi, 4.48 dBi and 3.86 dBi is obtained at 0.9 GHz, 1.8 GHz and 2.45 GHz, respectively. The proposed antenna is fabricated and |S11| dB is measured. Reasonable agreement between simulated results as well as measured results is obtained.

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.

High-Linearity 3-Bit Frequency-Tunable Planar Inverted-F Antenna for RF Applications

A compact planar inverted-F antenna (PIFA) has been designed, fabricated, and characterized to work either for receiving or transmitting applications. The antenna center frequency can be tuned from 1.52 up to 2.25 GHz, using switched auxiliary strips. Ohmic contact radio frequency microelectromechanical system (RF-MEMS) switches are used to connect and disconnect the auxiliary strips, maintaining both efficiency and antenna linearity (power handling capability). The measured PIFA efficiency for all states in an anechoic chamber is between 52% and 95%. The antenna linearity has also been measured using an adjacent channel power ratio test bench, showing 42-dB dynamic range up to 28-dBm input power.

Multiband Planar Inverted-F Antenna with Independent Operating Bands Control for Mobile Handset Applications

A new compact multiband PIFA (Planar Inverted-F Antenna) for mobile handset is proposed in this article. The proposed PIFA has a simple geometry with four slots integrated in the radiating patch and ground plane. The PIFA occupies a small volume of 51 × 14 × 7.2 mm3and is placed on the top portion of mobile phone. The optimized PIFA is worked in the 790 MHz band (737–831 MHz), the 1870 MHz band (1794–1977 MHz), the 2550 MHz band (2507–2615 MHz), and the 3400 MHz band (3341–3545 MHz), to cover LTE700, LTE800, DCS1800, PCS1900, LTE1800, LTE1900, LTE2500, and WIMAX3400 bands. Each of the four operating bands can be controlled independently by the variation of a single parameter of the proposed design, with a wide control range. An omnidirectional radiation pattern to each resonant frequency is obtained with a maximum gain of 2.15 dBi at 790 MHz, 3.99 dBi at 1870 MHz, 4.57 dBi at 2550 MHz, and 6.43 dBi at 3400 MHz. The proposed PIFA is studied in the free space and in the presence of other mobile phone components such as the battery, LCD (liquid crystal display), camera, microphone, speaker, buttons, and a plastic housing. The distribution of specific absorption rate for both European and American standards for each operating band and at various distances between the antenna and the human head is also studied.

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.

A novel extended edge-based compact PIFA antenna for mobile devices

In this paper, an optimized ultra-compact planar inverted F antenna (PIFA) is proposed. Planar inverted F antenna (PIFA) is most commonly used antenna in modern day Mobile devices. While electronics industry is starving for compactness in their design, the concept used in the proposed design further reduces size of antenna. The overall dimensions of proposed antenna are 14.94×16mm for 3G/4G standards. In proposed design 21.61% size reduction is reported in comparison to conventional rectangular patch PIFA designs. The concept can be further utilized in designing antenna for different standards by optimizing size for specific frequency. A fractal shape Patch shorted at one end is used in the proposed design. The fractal patch is extended 6.59mm above the ground plane. The comparison is performed between measurement of fabricated and simulated S11 for proposed antenna. The novelty of design is inherited in extension of edges of patch towards ground which enable further reduction in size of antenna. Parametric optimization of antenna is performed for calculation of extended edge dimensions. Return loss for fabricated antenna is measured using vector network analyzer. The results of fabricated antenna show good agreement with simulated results and calculations.

Development of wideband miniaturized antennas based on fringe field capacitance effects for implantable MedRadio band biotelemetry

A compact meander planar inverted-F antenna (PIFA) with a broad bandwidth, miniature size, and low profile is proposed for implantable biotelemetry in the Medical Device Radiocommunications Service (MedRadio) band (401-406 MHz). The tuning mechanism of fringe field capacitance effects in human tissues on broadband impedance matching and size reduction is also investigated. Compared to existing miniature antennas, the proposed antenna has a 37% smaller volume and provides a 166% wider bandwidth by cutting partial substrate. For the antenna simulation and design, the proposed antenna was embedded into a simple box model (with box size of 55 × 55 × 20 mm^3 and pork loin used as equivalent human tissue) and a male human body model (with Ansoft's accuracy of 4 mm). Experiments were also conducted. Although the proposed antenna occupies a volume of only 77 mm^3 (7.8 × 7.8 × 1.27 mm^3), the received power was as high as -47 dBm at 401 MHz. A communication link with distance of 1 m between the proposed implantable transmitting antenna and the exterior receiving monopole (one-quarter wavelength) antenna was set up.

QUAD-BAND PLANAR INVERTED-F ANTENNA (PIFA) FOR WIRELESS COMMUNICATION SYSTEMS

In this paper, a compact quad-band planar inverted-F antenna (PIFA) for wireless communication systems is presented. The proposed PIFA consists of a radiating patch with a hook- shaped slot and a modifled ground plane with pair of square-ring and rotated I-shaped slots. The antenna is fabricated on an FR4 substrate with dielectric constant of 4.4. By cutting a hook-shaped slit at radiating patch, good dual-band property can be achieved which covers 3.5GHz worldwide interoperability for microwave access (WiMAX) and 5.2GHz wireless local area network (WLAN) frequencies. In addition, by using a modifled ground plane with a rotated I-shaped an the pair of square-ring slot, additional resonances at the higher frequencies are generated which suitable for 7.25{7.75GHz downlink of X-band satellite communication systems and 8.02{8.4GHz international telecommunication union (ITU) applications. Good return loss, antenna gain and radiation pattern characteristics are obtained in the frequency band of interest. The proposed antenna has a small dimension of 24 £ 3 £ 1:6mm 3 .

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.

Low Sar Multiband CPW-Fed Pifa with Independent Resonant Frequency Control for Wireless Communication Applications

Low specific absorption rate (SAR) compact hexaband planar inverted-F antenna (PIFA) with independent resonant frequency control has been studied in this letter. Two trapezoidal-shaped slots are etched on the coplanar waveguide-fed PIFA-radiating plate to create two independent resonant frequencies as well as the fundamental PIFA itself. Three coupled slots are added within the ground plane to create an additional three independent resonant frequencies with slight effect on the other resonant frequencies. Multiband capabilities with bandwidth enhancement and acceptable SAR values are realized for different wireless communication applications. The SAR in the presence of human head is investigated by using CST 2012 Microwave Studio Hugo Voxil Model. The proposed antennas are fabricated, and there is a good agreement between measured and simulated results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1802–1810, 2013

Design of compact dual‐band quadruple planar inverted‐F antenna

Presented is a new compact dual-band quadruple planar inverted-F antenna (QPIFA) radiating right-hand circular polarisation characteristics. The size of the proposed dual-band QPIFA is 35 × 35 × 10 mm3 and the experimental results exhibit a peak gain of 2.5/4.5 dBic and an axial ratio under 1.5 dB in two target frequencies.