Planar Patch Antenna Research Articles

Design and Modeling of New UWB Metamaterial Planar Cavity Antennas with Shrinking of the Physical Size for Modern Transceivers

A variety of antennas have been engineered with MTMs and MTM-inspired constructs to improve their performance characteristics. This report describes the theory of MTMs and its utilization for antenna's techniques. The design and modeling of two MTM structures withε-μconstitutive parameters for patch antennas are presented. The framework presents two novel ultrawideband (UWB) shrinking patch antennas filled with composite right-/left-handed transmission line (CRLH-TL) structures. The CRLH-TL is presented as a general TL possessing both left-handed (LH) and right-handed (RH) natures. The CRLH-TL structures enhance left-handed (LH) characteristics which enable size reduction and large frequency bandwidth. The large frequency bandwidth and good radiation properties can be obtained by adjusting the dimensions of the patches and CRLH-TL structures. This contribution demonstrates the possibility of reducing the size of planar antennas by using LH-transmission lines. Two different types of radiators are investigated—a planar patch antenna composed of fourO-formed unit cells and a planar patch antenna composed of sixO-shaped unit cells. A CRLH-TL model is employed to design and compare these two approaches and their realization with a varying number ofL-Cloaded unit cells. Two representative antenna configurations have been selected and subsequently optimized with full-wave electromagnetic analysis. Return loss and radiation pattern simulations of these antennas prove the developed concept.

Radio frequency patch antenna reconfiguration with Ni–Ti shape memory alloy switches

Nickel–titanium shape memory alloys are employed to develop a multiband radio frequency antenna. Switches made from Ni–Ti electronically connect together a planar patch antenna arrangement, creating several electrical signal pathways that enable reconfiguration via resonance shifting. The changes in the antenna geometry, induced by the switches, create different working frequencies. The switches open and close due to an induced phase change from martensite to austenite via resistive heating from a separate electric circuit. A patch antenna was fabricated and then measured for S11 reflection coefficient, antenna gain, and radiation pattern at different configurations. The results show that the working frequency of the patch antenna arrangement is tunable from 2.25 to 2.43 GHz depending on the antenna geometry, while the antenna always maintains a high gain. The experimental results match well with simulations, indicating the potential for simulated design of future applications and geometries through shape memory actuators.

Low-profile circularly polarized GNSS antenna

In this article, we present a low-profile and low cost antenna for GPS (L1–L2–L5), Galileo (E5–E1–E2), and Glonass (G1–G2) standard. This antenna is a dual-feed planar patch antenna with four slots to achieve dual-band operation. The radiating element is fed by a wideband 90° quadrature hybrid coupler to obtain circular polarization on the both bands. The quadrature feeding is achieved using a three-branch-line hybrid coupler. The return loss bandwidth of the system (S11 ≤ −10 dB) is 22% in the lower band and 14% in the upper one. The axial ratio (AR) bandwidth in broadside direction (AR= 3 dB) is 20% in the lower band and 11.3% at the upper one. The antenna gain is 6 and 8.4 dBi in the normal direction at the central frequency of 1.23 and 1.6 GHz, respectively. The total dimensions of the antenna are 170 mm2 with a thickness of 7.524 mm. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2811–2814, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27175

Discrimination of wireless electromagnetic signals by electro-optic modulators using an array of patch antennas embedded with orthogonal gaps

We proposed a new wireless electromagnetic signal discrimination device using electro-optic modulators and an array of planar patch antennas embedded with orthogonal gaps. Wireless electromagnetic signals can be detected and converted directly to lightwave signals through optical modulation. The magnitude, phase, and polarization of the wireless signal can be measured precisely and identified. By using meandering gap structures, the directivity of the wireless signal conversion can be tuned more precisely. Furthermore, the directivity of the wireless signal conversion in two-dimensional space can also be obtained by comparing two orthogonal modulated lightwave signals from two orthogonal optical waveguides. The design and analysis of the device and experiments at an operational frequency of 26 GHz are presented.

Packages With Integrated 60-GHz Aperture-Coupled Patch Antennas

This paper presents balanced-fed and fork-fed aperture-coupled patch antennas and 16-element arrays suitable for broadband millimeter-wave communications. The antennas are realized in a multi-layer organic package structure, to which RF integrated circuits can be integrated. To improve antenna bandwidth and radiation efficiency, an air cavity is used, resulting in a superstrate planar patch-antenna structure. Additionally, resonating apertures are used to further increase the antenna bandwidth. Measured results at 60 GHz for the antennas show good performance in terms of peak gain (about 8 dBi for a single element and 17 dBi for a 16-element array), bandwidth ( >; 10 GHz for 10-dB return loss bandwidths are achievable), and radiation efficiency (80% for single-element from simulation).

A planar aperture-coupled patch antenna implemented on dashboard foams for intra-vehicle communication

A robust low-profile aperture-coupled quasi-circularly polarized patch antenna was designed for intra-vehicle communication in the unlicensed 2.45-GHz ISM band (2.4–2.485 GHz). As dashboards offer a large platform for invisible integration, the antenna is implemented using materials compatible with the production process of dashboards. This also allows easy, invisible, and low-cost integration inside a car's dashboard. A measured gain of 6.437 dBi and nearly circular polarization were obtained with the antenna covered by the different dashboard layers. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1186–1189, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25933

Planar compact inverted U-shaped patch antenna with high-gain operation for Wi-Fi access point

A planar compact inverted U-shaped patch antenna with high-gain operation for Wi-Fi system has been proposed and investigated.It provides relatively wider impedance bandwidth of 162 MHz covering the 2.45 GHz band (2400–2484 MHz). The proposed planar compact patch antenna also provides the directional radiation patterns with maximum peak antenna gain and efficiency of 7.5 dBi and 87% across the operating band, respectively. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:567–569, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25788

Development of Shared Aperture Dual Polarized Microstrip Antenna at L-Band

A simple technique to develop dual feed dual linearly polarized aperture coupled planar microstrip patch antenna at L-band frequency has been presented. A 4 × 2 array of aperture coupled square resonant patch antenna has been designed, fabricated and tested. The design optimization is carried out using commercial method of moment (MoM) based simulation software. The inter element spacing, inter-layer separation, isolation between the feeding ports, and other associated antenna parameters are optimized by successive simulations using the commercial software. Measured gain is better than 14 dBi. Measured results are also presented.

Development of Millimeter-Wave Planar Antennas Using Low-Loss Materials

As the importance of advanced millimeter-wave diagnostics increases, the fabrication of high-performance devices and components becomes essential. In this paper, we describe the development of millimeter-wave planar antennas using low-loss fluorine substrates. The problems to be solved in this study are the low degree of adhesion between copper foil and the fluorine substrate and the accuracy of device pattern using conventional fabrication techniques. In order to solve these problems, a new surface treatment of fluorine films and a fabrication method using electro-fine-forming (EF2) are proposed. In order to confirm the performance of the treated films, microstrip lines (MSLs) and planar patch antennas with a low sidelobe level in the E-plane are designed and fabricated on conventional fluorine substrates and grafted poly(tetrafluoroethylene) (PTFE) films.

Planar UHF RFID Tag Antenna With Open Stub Feed for Metallic Objects

An open stub feed planar patch antenna is proposed for UHF RFID tag mountable on metallic objects. Compared to conventional short stub feed patch antenna used for UHF RFID tag, the open stub feed patch antenna has planar structure which can decrease the manufacturing cost of the tags. Moreover, the open stub feed makes the impedance of the patch antenna be tuned in a large scale for conjugate impedance matching. Modeling and simulation results are presented which are in good agreement with the measurement data. Finally, differences between the open stub feed patch antenna and the short stub feed patch antenna for UHF RFID tag are discussed.

Integration of LED chip within patch antenna geometry for hybrid FSO/RF communication

A free space optical (FSO)/radio frequency (RF) dual mode communication transmitter using a LED integrated within the geometry of a planar patch antenna on a shared substrate is demonstrated. An experimental FSO link is constructed with a bare die visible LED and a commercial silicon photodetector. The antenna radiating at a centre frequency of 10 GHz, provides a simultaneously operated backup RF channel for the FSO data communication link to enhance reliability. A date rate of 20 Mbits is achieved for the FSO data communication.

슬릿 구조와 다층 구조를 이용한 소형 원형 편파 마이크로스트립 안테나

본 논문에서는 슬릿 구조와 다층 구조를 이용하여 소형 평판 안테나를 제안하였다. 제안한 안테나는 다층 FR4 기판을 이용하여 설계 및 제작하였으며 넓은 임피던스 대역폭을 갖는 소형 안테나로써, 가볍고, 저렴한 장점을 가지고 있으며 GPS 대역 중심 주파수 1,575.42 MHz에서 원형 편파 특성을 갖는다. 또한, 기판의 최상층의 슬릿의 길이와 폭을 조절하여, 대역폭을 거의 유지한 상태로, 공진 주파수를 낮추어 보다 소형화 하였다. 안테나 크기는 <TEX>$20{\times}20{\times}4.0\;mm^3$</TEX>이고 측정된 안테나 이득은 0.5 dBi, 대역폭은 VSWR 2:1에서 4.4 %(1,542<TEX>$\sim$</TEX>1,612 MHz), 3 dB 축비(axial-ratio) 대역폭은 약 15 MHz(1 %)이다. In this paper, a planar microstrip patch antenna is proposed using the slit on the top layer of a multi-layered structure for GPS application. The proposed antenna has a circular polarization at 1,575.42 MHz. This proposed antenna is fabricated on multi-layered FR4 substrate. The slits embedded on the top plane may yield to lower a resonance frequency and sustain a broad bandwidth. The proposed antenna size is <TEX>$20{\times}20{\times}4.0\;mm^3$</TEX>. The measured gain of 0.5 dBi, 10 dB bandwidth(VSWR 2:1) of 70 MHz(4.4 %), and 3 dB axial-ratio bandwidth of 15 MHz(1 %) have been obtained, respectively.

Wideband Planar Patch Antenna Array on Cylindrical Surface

The analysis of a capacitively fed wideband planar patch antenna array mounted on a cylindrical surface is presented. The antenna element used is in the shape of an octagon in which slots are placed on three of its sides. The elements are each fed by a small rectangular patch connected to a coaxial probe. On a cylinder of radius 100 mm, the single element is able to achieve an impedance bandwidth from 0.55 to 2.65 GHz, which is 131% of center frequency. When placed in an array environment, the bandwidth reduces slightly to 0.572.6 GHz, i.e., 128%. Simulation results, via two software packages, including S parameters, radiation patterns, and gain of the single element as well as those of the array are provided. A single- and a double-element antenna fabricated are tested, and results are compared with those of simulations. This antenna structure provides stable radiation patterns across the entire pass-band.

Shorted planar triangular patch antenna with dual-frequency operation

The characteristics of full and half-size V-slotted triangular patch antennas with shorting walls are investigated and compared in this paper. Both the antennas are dual-frequency radiate elements and they possessed impedance bandwidth of more than 8% at each operating frequency. For the full-size case, the radiation patterns at the lower and higher operating frequencies are conical and broadside, respectively. In comparison, both the operating frequencies of the half-size case exhibited the same broadside radiation patterns. Details of the measured and simulated results are presented and discussed.

New head exposure system for use in human provocation studies with EEG recording during GSM900‐ and UMTS‐like exposure

A new head exposure system for double blinded human provocation studies, which requires EEG recording during exposure with GSM900- and UMTS-like signals has been developed and dosimetrically evaluated. The system uses planar patch antennas fixed at 65 mm distance from the subject's head by a special headset, which provides minimum impairment of the test subjects and ensures an almost constant position of the antennas with respect to the head, even in case of head movements. Compared to exposure concepts operating small antennas in close proximity to the head, the concept of planar antennas at a certain distance from the head produces a much more homogeneous SAR distribution in the temporal and parietal lobe of the brain. At the same time the resulting uncertainty of exposure due to variations in head size, variations of the dielectric properties of tissues and unavoidable small changes of the antenna's position with respect to the head, is reduced to the order of approximately 3 dB, which is a significant improvement to comparable head exposure systems reported in literature in the past. To avoid electromagnetic interference on the EEG recording caused by the incident RF-field an appropriate double-shielded filter circuit has been developed. Furthermore, the effect of the presence of the sintered Ag/AgCl EEG electrodes and electrode wires on the SAR distribution inside the head has been investigated and was found to be minimal if the electrode wires are arranged orthogonal to the incident electric field vector. EEG electrode arrangement parallel to the incident field vector, however, might cause drastic changes in the SAR distribution inside the head.

Radar Interferometric Measurements With a Planar Patch Antenna Array

A planar patch antenna array has been made for radar interferometry. The antenna array consists of 32 rectangular patches on a ceramic loaded teflon substrate. The patches are individually coupled to the microwave electronics in two orthogonal circular polarizations. The radar interferometer is intended for topographic imaging in industrial environment, in this case, a blast furnace producing hot metal for the steel and metal industry. Ordinary imaging techniques with IR or visible radiation are not possible to use due to high temperatures, scattering from dust and particles. A model of blast furnace burden material surface was measured and detected.

System identification and model order reduction for TLM analysis

AbstractA system identification (SI) and Prony's model based algorithm for modelling and prediction of a time‐domain transient response is introduced and applied to time‐domain transmission line matrix (TLM) transient responses in order to extrapolate parameters of microwave circuits and accelerate the simulation process.Application of moment matching model order reduction (MOR) techniques to the TLM method is presented with emphasis placed on Krylov subspace methods based on the Lanczos process and its modifications. The Krylov subspace methods are attractive for MOR in the TLM framework because the construction of orthonormal and biorthogonal bases for correspondent Krylov subspaces can be carried out through a direct application of the implicit TLM solver. MOR applied to TLM allows one to generate a compact macromodel of a TLM‐system and significantly reduce the computational time.The efficiency and advantages of the SI and MOR techniques are demonstrated through their applications to the full‐wave analysis of different electromagnetic structures. In addition, a brief comparison of SI and MOR involved for modelling of a planar patch antenna is provided. Copyright © 2006 John Wiley &amp; Sons, Ltd.

A study of the wide-band L-probe fed planar patch antenna mounted on a cylindrical or conical surface

The characteristics of an L-probe fed planar patch antenna mounted on a cylindrical or conical surface are investigated in this paper. It is found that the wide-band characteristic of the L-probe patch antenna can be maintained with this structure and further enhanced by using a curved ground. An antenna mounted on a cylinder is built and measured to confirm the simulated results. A 10 dB impedance bandwidth of 45.2%, which is about 50% larger than that of the patch mounted on a flat ground plane, and a 3 dB beamwidth of 89/spl deg/ are achieved. This antenna, with a peak gain of 8.6 dBi, provides stable radiation patterns across the entire passband. Then an antenna with the same structure on a metallic conical ground is also evaluated. It is found that the bandwidth can be further improved when the antenna is mounted on a conical structure. The result is useful for the design of wide-band cylindrical antenna arrays with down tilted patterns.

Multiresonance planar patch antenna

A wideband compact microstrip antenna is designed using the method of moments (MoM) and experimentally evaluated. The VSWR bandwidth of the antenna is more than 90%, while its gain is above 2 dBi. The mechanism of operation of the antenna is also explained. The main advantage of this antenna is its wide impedance bandwidth. The limitation of the design is that the beam direction varies with frequency in the upper part of the bandwidth. This makes the antenna only suitable for wireless communication in a multipath environment. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 99–103, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20913

Asymptotic Evaluation of the Mom Excitation Vector for Probe-fed Microstrip Antennas

In this paper, we derive some original asymptotic expressions to speed up the computation of the excitation vector in the Method of Moments (MoM) numerical analysis of probe-fed planar microstrip antennas. These proposed expressions may be applied to the full-wave analysis of patch antennas in the spectral domain using the asymptotic Greens dyad of the planar integrated structure. It is shown in particular how planar patch antennas fed by a coaxial probe may be efficiently analyzed using fast converging 1D integrals to represent the MoM excitation vector, instead of employing the standard spectral bi-dimensional integrals. The numerical results underline the quick convergence of these new expressions and the consequent reduction of the computational time with respect to standard techniques.