Multilayer Patch Antenna Research Articles

A compact high gain filtering patch antenna for multiband wireless system

A novel compact multilayer patch antenna is designed for triple-band operation with filtering characteristics. The multiband antenna with filtering characteristics is necessary to suppress adjacent band interference. Further, it brings higher out-of-band suppression without deteriorating the in-band gain. This filtering antenna offers size compactness, high gain, and high selectivity with reduced interference. On exciting the antenna, the electromagnetic (EM) coupling takes place from feed to patch through the slotted ground. Then the magnetic field reaches its maximum at the middle of the rectangle patch while the electric field reaches its maximum at the edges. These fields couple with the ‘U’ shaped metallic loops and bring field distribution in it and thus contribute to dual-band resonance at 2.45GHz and 4.15GHz. For better impedance matching, the two ‘U’ shaped metallic loops are employed. The additional middle band at 3.25GHz is attained through the employment of a split rectangular ring around the center patch. The bottom ground is etched with a bent horizontal slot to achieve proper positioning of the lower resonance. The modified CRLH feeding structure is adopted in this antenna to realize radiation null between operating bands. The dimension of the CRLH branches decides the positioning of radiation nulls in the spectrum of interest. This null reduces the interband interference and it is an important feature for any multiband communication system. The usage of via between patch and feed increases the electrical length of an antenna and thus provides size miniaturization. Whereas the position of the via in the patch decides the impedance matching. thus multiple iterations of simulation were done to optimize the via position for better impedance matching. The designed antenna has a compact dimension of 0.21λo × 0.21λo. The realized triple bands have −10dB impedance bandwidth of 180MHz (2.31 to 2.49GHz), 350MHz (3.1 to 3.45GHz), and 850MHz (3.6 to 4.45GHz) with a maximum gain of 5.2dB. Thus the multi-layer antenna not only has proven to be multiband but also incorporated filtering characteristics to lessen interband interferences. The proposed antenna would be beneficial in a multiband wireless system that supports services such as Wifi, WiMAX, and 5G. The antenna is the perfect candidate for the unmanned ariel vehicle (UAV) to be used in emergency and military applications.

Investigation and design methods of a compact patch antennas using 3-D MMIC for various applications

This work focused on the design, characterization and investigation of GaAs based multi-layered compact 3D MMIC based antenna. Different patch antennas were designed and characterized along with its S-parameters. Two proposed models of multi-layered patch antenna using V-shaped feeder line and planar feeder line with a spiral transmission line in metal-2 were more compact in size and showed an improvement in performance based on bandwidth compared to the traditional planar feeder line configuration. This implies the proposed planar feed line with the spiral transmission is cost effective. The newly propose planar antenna with a spiral transmission feeder line is 49% more compact in area compared to using the normal planar feeder line. The new design also has wider bandwidth with a bandwidth of 2.99% as compared to the traditional planar with a bandwidth of 1.93%, better input return loss and a slightly lower resonance frequency. Similarly, another multilayer patch antenna was proposed using a V-shaped feeder line, This V-shaped feeder line antenna model showed a much lower resonance frequency (36.50 GHz) compared to normal planar (38.92GHz) and the planar with spiral transmission line model (38.52 GHz).

MULTIFREQUENCY STACKED PATCH ANTENNA ANALYSIS

In this paper, the theoretical and simulated results of a quad-band patch antenna without any air/foam gap between the dielectric layers are discussed. The design idea uses a skated dielectric layers to achieve a multi-frequency operation. The antenna under study includes four patches patterned on the top of layered dielectric substrates and is stacked vertically. Two pairs of spaced slits are embedded at the patch's radiation edges of the bottom and second patches to adjust the resonant frequencies. The resonant frequencies of the different patches are obtained at 4 GHz, 5 GHz, 6 GHz, and 7 GHz. According to the cavity theory and equivalent circuit approach, a theoretical model of the multilayer stacked patch antenna (MLSPA) is determined. Theoretical and simulated return loss plot is presented to validate the proposed design. The antenna parameters such as radiation pattern, gain, voltage standing wave ratio (VSWR), and beam-width are also discussed. Good impedance matching and radiation characteristics at the four operating bands make this antenna a good candidate for many applications. The antenna simulations are performed using a high frequency structure simulator (HFSS) 15.0 tool.

Hexagonal-Triangular Combinatorial Structure Based Dual-Band Circularly Polarized Patch Antenna for GAGAN Receivers

A multilayer gap-coupled dual band hexagonal microstrip patch antenna is presented for GPS Aided GEO Augmented Navigation (GAGAN) receivers. GAGAN is developed by AAI (Airport Authority of India) and ISRO (Indian Space Research Organization) exclusively for aviation purposes with the GPS frequencies L5 (1176.45 MHz) and L1 (1575.42 MHz). The proposed GAGAN antenna has three trapezoidal and four equilateral triangular patch resonators configured to form a gap-coupled hexagonal patch on the top layer and seven equilateral triangular patches with slots in between to form the middle layer. Both the layers are fed by a single coax feed to achieve a dual band compact microstrip antenna of size 55 mm x 55 mm x 3.2 mm. Instead of designing the hexagonal antenna conventionally from a circular patch antenna, the sides of the equilateral triangular patch are truncated to obtain the proposed compact hexagonal antenna as the triangular antenna occupies less area when compared to circular or square patches for a fixed frequency. To bring in novelty with improved performance, the combinatorial structured configuration has been explored through step-by-step optimization. The aspects of GAGAN requirements like circular polarization with a single input, dual band operation and high gain with gain flatness are achieved with this compact structured antenna when compared to square and circular patch antennas. The combinatorial structures such as perturbation and truncation introduced in the patches are responsible for exciting two near-degenerate orthogonal modes producing circular polarization (CP). A cross slot etched in the center patch results in gain enhancement with a gain above 3.2 dBi over a bandwidth of 20 MHz in both the bands. Five shorting pins are added to achieve high impedance matching and good CP with an axial ratio (AR) below 2 dB. The simulated and measured results are found to be in good agreement with greater than 20 MHz operational bandwidth exhibiting CP with an omni-directional radiation pattern having high cross polar levels of -22 dB. The size reduction achieved in the proposed design is 56.79% when compared to the conventional hexagonal patch antenna. The measured 10 dB impedance bandwidth is 2.7% and 2.1% for L5 and L1 bands respectively with a 3 dB AR bandwidth of 2.3% for L5 and 2.0% for L1, satisfying GAGAN requirements.

A compact, low-profile, and high-performance monopulse antenna array for missile seeker

In this paper, the authors presented a compact, low-profile, and high-performance ku-band monopulse antenna array (MAA) for missile seekers with reduced complexity involved in fabrication, assembly, and installation. They investigated a multilayered microstrip patch Antenna technology by systematically developing an efficient synthesis process, high-performance design of radiating elements as well a feed network integrated with monopulse circuitry, and innovative multiple layered joining processes, which overcome limitations of the existing MAA system. Optimum aperture distribution corresponding to desired radiation characteristics is synthesized using a hybrid synthesis technique in which collapse distribution (CD) is employed to initialize the Genetic Algorithm (CD-AvGA). The authors designed the proposed MAA with computed coefficient and carried out fabrication, assembly, and functional validation. The obtained experimental results are in close agreement with simulated ones and satisfy the missile seeker’s stringent functional and platform requirements.

Magnetless nonreciprocal filtering diplexing antenna

AbstractThis paper presents a magnetless nonreciprocal diplexing antenna that uses time modulation. The device combines the functions of diplexers, filters, isolators, and antennas in a highly integrated manner. The magnetless nonreciprocity response is achieved by applying time modulation to the resonators of the filtering structures. These resonators are implemented in quarter‐wavelength microstrip lines terminated with varactors that are time modulated by low‐frequency signals fed from Coplanar Waveguides built on the ground plane of the microstrip structure. A prototype multilayer patch antenna is fabricated, which is fed through two orthogonal feedlines and the radiating square patch is coupled by a square ring slot etched in the ground plane. The experimental results show that a gain of 4 dB, out‐of band rejection of 22 dB, in‐band isolation of 20 dB, and inter‐port isolation of 35 dB is obtained at both 1.5 GHz (lower band) and 1.8 GHz (higher band).

Miniaturized Dual-Band Broadside/Endfire Antenna-in-Package for 5G Smartphone

This paper proposes a miniaturized antenna in package (AiP) for 5G millimeter-wave smartphone that incorporates broadside and end-fire arrays and supports a dual band covering 28 and 39 GHz. This paper demonstrates that the proposed AiP is 5.8 mm × 19 mm × 1.122 mm. It is believed that this is the smallest 5G AiP that can support a 10 dBi antenna gain, a 10 dB return-loss bandwidth of 3 GHz, and more than 10 dB isolation for both broadside and end-fire arrays. AiP consists of a 1 × 4 patch antenna array for broadside radiation and a 1 × 4 dipole antenna array for end-fire radiation. To miniaturize the patch antenna elements, a multi-layer Reactive Impedance Surface (RIS) is embedded between the patch layer and the ground plane. This multi-layer RIS idea greatly fits in 5G PCB-stack up antennas where each stack-up layer essentially requires certain portion of copper area. For the end-fire array antenna miniaturization with bandwidth improvement is achieved by modifying the Vertically Bent Folded Dipole Antenna (VBFDA) and adding a tightly-coupled T-shape side via wall. The AiP achieves a 10 dB return-loss bandwidth of 26.22 to 29.57 GHz and 35.18 to 41.00 GHz for Multi-Layer RIS Patch Antenna(MLRPA), and 26.40 to 29.74 GHz and 36.65 to 40.72 GHz for VBFDA. The antenna gain is 11.6 dBi for MLRPA and 10.0 dBi for VBFDA.

UWB Multilayer Patch Antenna with EBG Structure for IEEE-C, X, Ku and K Band Applications

UWB Multilayer Patch Antenna with EBG Structure for IEEE-C, X, Ku and K Band Applications

2 × 2 Textile Rectenna Array with Electromagnetically Coupled Microstrip Patch Antennas in the 2.4 GHz WiFi Band

The development of e-textiles is fostering research in wireless energy transmission. This paper presents a purely textile 2.4 GHz WiFi band 2 × 2 rectenna array for RF energy harvesting. It utilizes the electromagnetically coupled microstrip patch antenna topology and a simple and precise construction method that provides a good performance repeatability to create multilayer microstrip textile patch antennas. The rectifier is implemented with Schottky diodes and it takes the voltage doubling configuration. An average DC power of 1,1 mW was measured for 14 μW/cm2 of RF input power density, while the end-to-end average power conversion efficiency (PCE) measured was 31%. The characterization of the end-to-end PCE was evaluated considering the physical size of the prototype to make the comparison with other designs easier. Measurements in a real WiFi scenario were also performed, demonstrating its feasibility for feeding e-textiles.

Broadband and efficient patch array antenna fed by substrate integrated waveguide feed network for Ku‐band satellite applications

A new class of multi-layer microstrip patch antenna (MPA) array fed by substrate integrated waveguide (SIW) cavities is presented for Ku-band applications. An efficient compact multi-layer SIW feeding network is designed, which has lower losses than the conventional corporate feeding network based on microstrip lines or coplanar waveguides. A 4 × 4 array consists of four stacked layers, including three based on the SIW technology as a feeding network and one layer for the radiating antenna array. Each layer can easily be fabricated from a dielectric substrate and processed using the printed circuit board (PCB) technology. Afterward, all the PCB laminates are stacked together and tied by screws. The measured antenna operates from 11.2 to 13.6 GHz achieving 19.35% bandwidth. The measured peak gain at 12.5 GHz is 17.1 dBi, equivalent to 71.47% aperture efficiency. The fabricated array exhibits several advantages: broadband, low cost, compactness, high radiation efficiency, high aperture efficiency, and lightweight, which makes it a candidate for Ku-band satellite applications.

Decoupled Monitoring Method for Strain and Cracks Based on Multilayer Patch Antenna Sensor.

As the rapid development of high-end intelligent equipment continues, the design requirements for crack and strain monitoring equipment are increasing daily. In this paper, a decoupled monitoring method for strain and cracks based on a multilayer patch antenna sensor is studied. First, the monitoring principle for strain and crack decoupling is analyzed. Second, the design method for the multilayer patch antenna sensor is studied, and the hierarchical arrangement, patch size, substrate layer thickness, and feeding line structure are designed on the basis of this method. A quarter-wavelength impedance converter is designed to perform impedance matching and optimize the resonant frequency information. The effects of strain and crack propagation on the resonant frequency of the patch antenna are analyzed through simulations, and the decoupled monitoring method for the structural stress state and crack propagation is discussed. Lastly, the feasibility of decoupled monitoring of strain and cracks is verified experimentally. The results of the theoretical analysis, simulations, and experiments show that the proposed patch antenna sensor based on the multilayer structure can realize decoupled monitoring of strain and cracks in the structure, and the sensor has broad application prospects.

An X-Band Substrate Integrated Waveguide Fed Patch Array Antenna: Overcoming low efficiency, narrow impedance bandwidth, and cross-polarization radiation challenges

In this article, the efficient development of a new class of multilayer microstrip patch antenna (MPA) fed by a substrate integrated waveguide (SIW) for X-band applications is presented. It consists of performing the feed network in the SIW and the radiating structure in the microstrip technology. The proposed structure demonstrates that the best alternative to a costly, heavy, and bulky rectangular waveguide feeder is an SIW, which provides miniaturization, performance enhancements, cost reductions, and ease of integration with MPAs. The proposed patch array is composed of three stacked layers from top to bottom, including two SIW layers as a feeding network and one layer as the antenna layer. To verify the concept of the proposed antenna, a prototype of a 2 × 2 SIW patch array with a 39 × 41 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> physical aperture was fabricated and measured with an impedance bandwidth of 9.18% for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\left|{{S}_{11}}\right|{&lt;}{-}{10}\hspace{0.33em}{\text{dB}}$</tex-math></inline-formula> and a radiation efficiency above 78% in the whole operating frequency bandwidth. The maximum measured gain of the proposed array at 10 GHz is 11.1 dB, which is equivalent to 57.7% of the aperture efficiency. The proposed array can be easily developed to be used in larger arrays, and it is a good candidate for generating a symmetrical unidirectional pattern with a low cross-polarization level.

Design of a Cylindrical Crossed Dipole Phased Array Antenna for Weather Surveillance Radars

We present a cylindrical dual-polarization phased array antenna for weather surveillance radars that features high isolation, matched copolar beams, low sidelobe levels, and adaptive null steering. We present a crossed dipole antenna element to replace the patch antenna on the currently deployed cylindrical polarimetric phased array radar (CPPAR). The crossed dipole element offers suppressed surface wave and lower coupling between adjacent elements of an array. As a result, we achieved lower backlobe and sidelobe levels, and a higher match between copolar beams of CPPAR compared to the currently deployed multi-layer patch antenna. Further reduction of the sidelobe level and adaptive null steering are obtained using a modified particle swarm optimization. The proposed null steering mitigates the interference among the four concurrent beams of a cylindrical phased array radar. The improvement in CPPAR radiation characteristics has been verified by comparing the presented crossed dipole antenna’s radiation patterns and the existing aperture coupled patch antenna. The proposed crossed dipole phased array can benefit national weather radar networks to provide accurate multiparameter measurements enabling reliable observation of severe weather phenomena.

Design of Wideband Differentially Fed Multilayer Stacked Patch Antennas Based on Bat Algorithm

A new approach for the design of wideband multilayer stacked patch antennas is proposed based on the bat algorithm. Differential topology is described for multilayer stacked patch antennas to achieve the stable and symmetry radiation patterns as well as the high cross-polarization (XP) suppression within the design band. The fabricated antenna prototypes show 25.5% and 34.9% impedance bandwidth for the two-layer and three-layer designs, respectively. The measured results validated the design.

Designing and Analysis of CPW-Fed Multi-Layer Patch Antenna with Partial Defected Ground Plane for K/Ku-Band Satellite Applications

In this work a CPW-fed ultra-wideband microstrip patch antenna is presented by using the concept of stacking of substrates of different dielectrics with partial defected ground. The proposed porotype having multilayer (three layers) configuration consists of two substrates (FR-4 epoxy with relative permittivity of 4.4 and air with relative permittivity of 1) as dielectric medium. The stacking and defected ground plane is used to boost the impedance bandwidth and gain. The Modeling demonstration and reproduction of the antenna has been carried out by 3-dimensional electromagnetic solver ansoft high frequency structure simulator HFSS-16. The operating frequency range of the presented model is 11.4 GHz to 18.0 GHz; thus, the antenna is applicable to Ku band applications. Antenna performance is discussed in terms of S11 (dB), gain and radiation efficiency.

Wearable Multilayer Patch Antenna with Electromagnetic Band Gap Structure for Public Safety Systems

ABSTRACT For providing security to the people, who survive in country borders, mine and chemical industries, wearable devices with sensors can be used to follow their activities through sensors. The main element of that security device is the antenna. Based on the construction, utility, and performance, miniaturized MicroStrip Patch (MSP) antennas are mainly preferred. In this paper, the compact MSP antenna design, using various flexible multilayer substrate materials with Electromagnetic Band Gap (EBG) structures, has been proposed to resonate at 2.45 GHz in ISM band. The simulated and the measured parameters have been analyzed and an improvement in gain up to 6 dB has been achieved compared to the existing technique.

Reliable Lab-Scale Construction Process for Electromagnetically Coupled Textile Microstrip Patch Antennas for the 2.45 GHz ISM Band

A precise layer alignment is crucial to ensure performance repeatability of multilayer microstrip antennas. We introduce a novel lab-scale construction process for multilayer microstrip textile patch antennas that consists in combining an alignment method, based on laser-cut wood frames to perform accurate layer alignment, with a fast intralayer attachment method, based on thermally activated adhesive sheets. This lab-scale construction process is validated with an electromagnetically coupled microstrip rectangular patch textile antenna operating in the 2.45 GHz ISM band. It has been reproduced eight times to validate the proposed construction process. The differences between desired simulated versus measured average values of the resonant frequencies, impedance bandwidths, gains, and total efficiencies equal 6.25 MHz, 21.5 MHz, 0.6 dBi, and 4.45%, respectively. Moreover, the standard deviations of measured resonant frequencies, impedance bandwidths, gains, and total efficiencies equal 24.54 MHz, 14.02 MHz, 0.15 dBi, and 3.57%, respectively. These results confirm that the novel lab-scale construction process provides good performance repeatability of multilayer microstrip textile patch antennas.

Multi-Layer PCB Bow-Tie Antenna Array for (77–81) GHz Radar Applications

In this article, a new wideband cavity-backed bow-tie microstrip antenna is presented for short-range 77–81 GHz radar applications. The design is based on a subarray consisting of two single elements. Each element consists of a multilayer bow-tie patch antenna surrounded by a metallic cavity to suppress the surface waves and parallel plate modes. The subarray elements are fed through a laminated waveguide with 180° phase shift. An eight-layer build-up and a new advanced multilayer PCB technology, the so-called any-layer PCB technology, is used for the fabrication. The performance of this antenna has been verified by both simulations and measurements. A bandwidth of more than 8% is achieved. The gain is 7.9 dBi, and the radiation efficiency is 70% at 79 GHz. Beam widths of 84° in the E-plane and 48° in the H-plane are obtained, which are compatible with radar requirements for short-range applications.

Direct and electromagnetically coupled compact microstrip antenna design with modified fractal DGS

This article proposes ultra-miniature microstrip patches with direct and electromagnetically coupled feeding mechanism for wireless communications at 10 GHz. Antenna size reduction is achieved here by loading a modified Minkowski fractal (type-2) defected ground structure (MFDGS-II) exactly beneath the radiating patch. The proposed method involves the selection of best DGS configuration through sensitivity analysis of the antenna structure. From different applications point of view, three different designs: a single layer direct fed patch and two electromagnetically coupled fed multi-layered microstrip patch antennas are proposed here and designed with MFDGS-II. The resonant frequencies of the antenna designs are reduced in a significant manner incorporating MFDGS-II without any change in the physical size of the antenna. The prototypes of the proposed antennas are fabricated, and the performance parameters are measured. Compared with other existing structures, with a lower patch size of 0.20 λ0 × 0.15 λ0, the proposed single layered antenna with microstrip feed achieves a patch size reduction up to 67% and an overall volumetric reduction of 84%, respectively. Similarly, the proposed multi-layered patch with proximity feed exhibits a maximum impedance bandwidth of 600 MHz and the aperture coupled fed patch has a realized gain of 6.2 dBi with radiation efficiency of 91% centered at 10 GHz. All three proposed compact antenna structures are best in three different aspects and have the potential to meet the practical requirements for X-band portable wireless applications.

A Transmitter System-in-Package at 300 GHz With an Off-Chip Antenna and GaAs-Based MMICs

This paper presents a novel transmitter system for applications operating in the frequency region around 300 GHz. A relatively simple packaging approach is taken, allowing for a variety of integrated or embedded applications. This paper presents a multilayered stacked patch antenna on quartz with a dielectric lens, functioning in tandem with a GaAs-based multiplier chain. When operating, an input signal between 7.8 and 8.6 GHz is multiplied 36 times to a frequency range between 280 and 310 GHz, via two in-house fabricated GaAs-based monolithic microwave integrated circuits (MMICs). The antenna is fabricated on quartz wafers via an in-house process. Both, the MMICs and the antenna, are placed on a printed circuit board. A high-density polyethylene lens encloses the system-in-package (SiP), with a footprint of 1 cm $^{2}$ . The SiP has a center frequency of 300 GHz and an absolute pattern bandwidth of 21 GHz. The measured antenna gain along the broadside is 23 dBi, which corresponds to an equivalent isotropic radiated power of 20 dBm. This is achieved with 0.3 W power consumption. The design, simulation, and the analysis are performed via an electromagnetic simulation and modeling tool (Computer Simulation Technology Microwave Studio). Both, separate measurement data for the individual parts of the SiP and complete system experimental characterization are included in this paper.