Aperture-coupled Microstrip Patch Antenna Research Articles

Performance Improvement of Aperture Coupled MSA through Si Micromachining

In recent times rectangular patch antenna design has become the most innovative and popular subject due to its advantages, such as being lightweight, conformal, ease to fabricate, low cost and small size. In this paper design of aperture coupled microstrip patch antenna (MSA) on high index semiconductor material coupled with micromachining technique for performance enhancement is discussed. The performance in terms of return loss bandwidth, gain, cross-polarization and antenna efficiency is compared with standard aperture coupled antenna. Micromachining underneath of the patch helps in to reduce the effective dielectric constant, which is desirable for the radiation characteristics of the patch antenna. Improvement 36 percent and 18 percent in return loss bandwidth and gain respectively achieved using micromachined aperture coupled feed patch, which is due to the reduction in losses, suppression of surface waves and substrate modes. In this article along with design, fabrication aspects on Si substrate using MEMS process also discussed. Presented antenna design is proposed antenna can be useful in smart antenna arrays suitable in satellite, radar communication applications. Two topologies at X-band are fabricated and comparison between aperture coupled and micromachined aperture coupled are presented. Index Terms—Microstrip Patch Antenna, Aperture Coupled, Micromachining, High Resistivity Silicon

Low Cost High Gain 8×8 Planar Array Antenna for 5G Applications at 28GHz

In next-generation mobile networks, hundreds of diverse devices aim to be interconnected, posing huge challenges in capacity, coverage, efficiency, reliability, and connectivity. These and other challenges are addressed at Radio Frequency (RF) parts such as several radiating unit antennas, with very fine beamforming capabilities along with the requirements of high gains and minimized size. This work presents an 8×8 Aperture Coupled Microstrip Patch Antenna (AC-MPA) in the form of a planar array modeled for the 28GHz frequency band with high gain and compact size, making it suitable for 5G networks. The antenna is designed using a substrate with overall dimensions of 74.6×85.648×0.107mm3 and relative permittivity of ε0 = 4.3.

A Low-Profile Dual-Band Patch Antenna With Simultaneous Wide Beamwidth and High Gain by Using Multiresonant Modes

A low-profile aperture-coupled microstrip patch antenna (MPA) under multiresonant modes for wide half-power beamwidth (HPBW), high gain and enhanced-bandwidth is proposed. Firstly, the radiation patterns of the MPA are studied to improve the radiation performance. It demonstrates that the HPBW of the lower TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> mode could be progressively widened by properly selecting the dielectric constant of the substrate. Meanwhile, by etching a rectangular slot, the high sidelobe in E-plane of the upper TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">30</sub> mode could be obviously reduced, resulting in enhancing the normal gain. Secondly, the improved feeding network is introduced and studied. The results show that the impedance bandwidth of the antenna is successfully extended over dual operating bands. Finally, the proposed antenna is fabricated and tested. Experimental results show that the antenna has improved-bandwidths (| <italic 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">11</sub> | < –10 dB) with two-minimum poles in the range of 1.42–1.45 GHz for the lower band and 3.95–4.13 GHz for the upper band, respectively, which is about two times wider than that of the traditional counterpart. Besides, the antenna maintains the small thickness of about 0.02 free-space wavelength. Particularly, the wide E-plane HPBW and broadside gain of the MPA are simultaneously enhanced to around 130° and 9.0 dBi at the lower and upper bands, respectively.

Analytical Model to Calculate the Impedance Bandwidth of a Microstrip Patch Antenna (MPA)

The aim of this paper work to design and analyzed a compact size Microstrip patch antenna. The conducting patches like rectangular and circular configurations are most commonly used for configurations. Mostly microstrip patch antenna is performed with narrow bandwidth. Here, an analytical mathematical model is used to calculate the impedance bandwidth, which improves the bandwidth of an antenna. In this paper Impedance Bandwidth of an Aperture Coupled Microstrip Patch Antenna (AC-MPA) using an accurate analytical model. The proposed mathematical model is used to calculate the impedance bandwidth of the antenna with high accuracy. MSP is mainly focused on the design of the compact-sized wideband Microstrip antenna. The return loss is -36.8785dB from 2 GHz to 4 GHz frequency with a bandwidth of 0.28 GHz. A maximum gain of 20 dB is achieved at 3.45 GHz frequency.

An 8×8 mm-Wave LP ACMPA Array for a Long-Range mm-Wave Chipless RFID Tag-Sensor Reader

An $8{\times }8$ linearly-polarized (LP) aperture-coupled microstrip patch antenna (ACMPA) array is presented for a long-range millimeter (mm)-wave chipless RFID tag-sensor reader. This antenna array is capable of reading the linearly-polarized (LP), orientation-insensitive (OI), and cross-polarized (CP) chipless RFID tags and sensors in the mm-wave frequency band from a long distance. A systematic approach is followed for developing the LP ACMPA array, which operates over the 22–27 GHz frequency band with 22 dBi gain. At first, a single antenna element is designed, which is followed by the design of a 1–64-way corporate feed network. Then, the $8{\times }8$ mm-wave LP ACMPA array is designed, optimized, fabricated, assembled, and tested. After that, the assembled antenna is used for measuring ten thermal printed mm-wave OI tags on paper from 30 cm and three CP tags on Taconic from 200 cm distance to validate its functionality in long-distance tag reading. Finally, the effects of different parameters on LP ACMPA are studied, which are used next for developing a novel step-by-step guideline for designing the LP ACMPAs with a new set of specifications. This high gain antenna array can be used commercially in a long-range mm-wave chipless RFID tag and sensor reader due to its low profile, low-cost, and lightweight structure.

Ultra-wideband Aperture Couple Microstrip Patch Antenna for Ka and Q Band Applications

A novel and small size (900 mm2) aperture coupled microstrip patch antenna is proposed in this paper. Two substrates (FR4 and Bakelite) are used in antenna design to enhance the antenna parameters. The parameters of the proposed antenna are return loss, gain, VSWR, radiation pattern, radiation efficiency and group delay is analyzed by electromagnetic simulation tool (HFSS by ANSYS). The proposed antenna resonates in multiple bands in the frequency range of (22.2-62 GHz) with one wideband and one UWB operation. Impedance bandwidth of 14%, 48%, 9% and 4.9% and gain of 7.6 dBi, 12.7 dBi, 8.2 dBi and 5.1 dBi are observed in (22.2-25.7) GHz, (31.852) GHz, (53-58) GHz and (59-62) GHz bands respectively.

Design and analysis of aperture coupled micro strip patch antenna for radar applications

The aperture coupled- Micro strip Patch Antenna (AC-MPA) is designed for long range (≈400 ​km) air Surveillance radars. The design of patch antennas with aperture coupled power feed is crucial and designed for 1 ​GHz–2 ​GHz (D-band) frequency. The proposed aperture coupled feed design gives wideband behavior, better return loss, gain, Voltage Standing Wave Ratio (VSWR), less compatibility and smaller in size by applying aperture feed. The theoretical analysis is done manually and designed using Advanced Design System (ADS). In aperture coupled feeding technique, the input signal couples to the radiating patch through the aperture (slot) that appears on the ground plane of the feed line and with their feeding structure of the radiating patch element it is different from other micro strip patch antenna. In this work, the design and implementation of aperture coupled patch antenna are analyzed in terms of return loss, gain, efficiency, directivity and power parameters and compared with inset line feeding. The proposed design gives 5 ​dB gain, 4.5 ​dB directivity, efficiency of 30%, impedance bandwidth of above 15% higher than inset feed line with 1.5 ​GHz as centre frequency. The maximum return loss of-40dB is achieved compared to −19dB with aperture feed compared to inset feed line micro strip patch antenna with proper impedance matching. The main advantage of this antenna over single layered patch antenna is increased bandwidth and this antenna will act as dual band also with variation in air gap (1 ​mm–5 ​mm) between single and aperture coupled patch antenna.

Comparative Study of Optimization Algorithms on the Design of Broadband Antennas

Broadband antennas find many applications in modern communication systems, such as Wi-Fi, 5G, and SatCom. Multiple competing optimization methods are available for the application to antenna design, while it would be preferable to know in advance if any method is superior. Here, an application of the cross-entropy method, along with particle swarm optimization and covariance matrix adaptation evolutionary strategy, to the design of broadband antennas is presented. The first example is an aperture-coupled microstrip patch antenna that has 9.5 dBi peak directivity and 53% bandwidth after optimization. It is then used as a feed in a high-gain broadband resonant cavity antenna. Using an all-dielectric superstrate with a transverse permittivity gradient, a compact thin resonant cavity antenna with a peak directivity of 19 dBi and 40% 3-dB bandwidth was designed. A comparative analysis of the cross-entropy method, particle swarm optimization, and covariance matrix adaptation evolutionary strategy applied to these two problems was carried out to provide the basis for further optimization of antennas in radio frequency and microwave frequency bands. We found that although all three methods reached a similar solution, the cross-entropy method has a speed advantage. It improves our ability to optimize existing designs and has wider applicability beyond antenna engineering.

Dual‐polarised hybrid feed microstrip patch antenna for multifunction application

In this Letter, a dual-polarised aperture-coupled microstrip patch antenna with low cross-polarisation and high isolation is presented. A microstrip patch antenna is designed and fabricated to meet the multifunction phased array radar requirements. The proposed single element is fabricated and the measurement results along with simulation results have been presented, showing the performance of the designed single element. An input isolation of better than 50 dB and a cross-polarisation level of <;-30 dB are achieved in the measurements.

Higher-order mode substrate integrated waveguide cavity excitation for microstrip patch antenna arrays at 30-GHz

This paper presents a novel approach to the design and fabrication of low-cost and high-gain aperture-coupled microstrip patch antenna (AC-MPA) arrays with improved radiation pattern for millimetre-wave applications such as simultaneous wireless information and power transfer (SWIPT) and Internet-of-Things (IoT) device connectivity. A higher-order mode substrate integrated waveguide (SIW) cavity is used to feed the MPA arrays through aperture coupling. The improved design approach is introduced and discussed in detail. Simulation and experimental results for 2 × 2 and 4 × 4 arrays are presented, demonstrating excellent agreement. Key performance metrics are side-lobe levels of less than −24 dB and −29 dB in the E-plane and −22 dB and −26 dB in the H-plane and realized gain of 11 dBi and 15 dBi for the 2 × 2 and 4 × 4 arrays respectively, at a design frequency of 30 GHz.

Low Cross-Polarization, High-Isolation Microstrip Patch Antenna Array for Multi-Mission Applications

The design and development of a high-performance, dual-polarization, hybrid aperture-coupled microstrip patch antenna are presented. In the presented design, the horizontal and vertical polarizations are excited using the aperture coupling method. The isolation level of better than 51 dB and cross-polarization level of less than −30 dB are achieved from the measurement results of the designed single element. To achieve better cross-polarization levels, the $2 \times 2$ element subarrays of the proposed unit cell, while the horizontal polarization ports are mirrored, are designed and fabricated, and a lower than −39-dB cross-polarization level is achieved in the measurement results. Finally, to characterize the scan performance of the unit cell and subarray, a $4 \times 10$ element array of the proposed single element is fabricated and a better than −45-dB cross-polarization level is observed while scanning up to 45°.

Design and Development of 6 Elements Aperture Coupled Feed Planar Array Rectangular Microstrip Patch Antenna for CPE WiMAX Application at 3.3 GHz

Design and Development of 6 Elements Aperture Coupled Feed Planar Array Rectangular Microstrip Patch Antenna for CPE WiMAX Application at 3.3 GHz

비대칭 개구면 결합 급전을 이용한 원형편파 마이크로스트립 패치 안테나 설계

비대칭 개구면 결합 급전을 이용한 원형편파 마이크로스트립 패치 안테나 설계

Effect of mutual coupling between feed elements on integrated lens antenna performance

An integrated lens antenna (ILA) equipped with a beam-switching array feed provides beam-steering. This study investigates the effects of the mutual coupling between the feed array elements on the ILA performance. A simulation study of an ILA with two different feed types with varying mutual coupling levels is done. Radiation pattern and boresight directivity of the ILA are in the prime focus of the study. An aperture-coupled microstrip patch antenna (ACMPA) and a stacked ACMPA feeds embedded in an array are used to study the radiation characteristics of the ILA. Results show that changes in directivity and radiation pattern of the feed caused by the mutual coupling have significant impact in the ILA characteristics. However, it is found that the mutual coupling level alone does not predict well the changes in the ILA radiation. Among two feed antenna types with similar mutual coupling variation, the stacked ACMPA feed with less radiation pattern distortion gives better ILA performance compared to the ACMPA feed with significant radiation pattern distortion. Furthermore, impact of the port impedance mismatch of the adjacent inactive antennas on the active element performance of a beam-switching feed network and its corresponding impact on the ILA is investigated.

Circuit Theory Analysis of Aperture Coupled Patch Antenna for Wireless Communication

An analysis of dual band aperture coupled microstrip patch antenna is performed using modal expansion cavity model. The theoretical investigation of antenna characteristics such as return loss, VSWR and radiation pattern is represented. The influence of geometric parameters of the aperture coupled microstrip patch antenna, such as aperture length and width, height of the substrate, dielectric constant are also investigated. It is found that antenna resonates at two distinct modes i.e. 4.39 and 5.55 GHz for lower and upper resonance frequencies respectively. The bandwidth of the aperture coupled microstrip patch antenna at lower resonance frequency is 10.23% (theoretical) and 13.33% (simulated) whereas at upper resonance frequency, it is 5.69% (theoretical) and 3.59% (simulated). The frequency ratio obtained for upper to lower resonance frequencies for theoretical and simulated results are 1.5 and 1.37 respectively. The theoretical results are compared with IE3D simulation results along with reported experimental results and they are in close agreement.

Performance enhancement of a compact wideband patch antenna array using EBG structures

In this paper, a compact wideband linear microstrip phased array antenna (MPAA) is proposed. To reduce the size of MPAA, a compact wideband aperture coupled microstrip patch antenna (MPA) is utilized as array element. Size reduction of the array element is performed through incorporating an interdigital capacitor (IDC) in the patch and a metamaterial (MTM) unit cell close to slot in the ground plane of the antenna. By cutting two vertical slits from the slot, further compacting of the slot in the ground plane of array element is obtained. By this technique dimensions of the patch and slot are reduced by 12.9% and 12.2%, respectively. Furthermore, dimensions of the MPAA are reduced through decreasing the spacing between array elements causing the antenna performance degradation. To overcome this shortage and improve the radiation characteristics of the proposed MPAA, an electromagnetic bandgap structure (EBG) is utilized. The effect of implementing EBG cells on the reflection coefficient of the elements in the MPAA during beam scanning is studied in details. The maximum measured gain, bandwidth and cross-polarization level of the fabricated MPAA are 13.3 dBi, 24.4% and −40 dB, respectively making it a good candidate for monopulse tracking radar applications. The measurement results confirm the simulation results.

A wireless passive pressure sensor based on aperture coupled microstrip patch antenna

PurposeThis paper aims to present a novel wireless passive pressure sensor based on an aperture coupled microstrip patch antenna embedded with an air cavity for pressure measurement.Design/methodology/approachIn this paper, the sensitive membrane deformed when pressure was applied on the surface of the sensor and the relative permittivity of the mixed substrate changed, resulting in a change in the center frequency of the microstrip antenna. The size of the pressure sensor is determined by theoretical calculation and software simulation. Then, the sensor is fabricated separately as three layers using printed circuit board technology and glued together at last. The pressure test of the sensor is carried out in a sealed metal tank.FindingsThe extracted resonant frequency was found to monotonically shift from 2.219 to 1.974 GHz when the pressure varied from 0 to 300 kPa, leading to an average absolute sensitivity of 0.817 MHz/kPa.Research limitations/implicationsThis pressure sensor proposed here is mainly to verify the feasibility of this wireless passive maneuvering structure, and when the base material of this structure is replaced with some high-temperature-resistant material, the sensor can be used to measure the pressure inside the aircraft engine.Originality/valueThe sensor structure proposed here can be used to test the pressure in a high-temperature environment when the base material is replaced with some high-temperature-resistant material.

Low cross‐polarisation high‐isolation frequency scanning aperture coupled microstrip patch antenna array with matched dual‐polarisation radiation patterns

A method of beam matching between two linear polarised radiation patterns of a dual-polarised frequency scanning antenna is proposed, implemented, and tested. A meticulous phase match process between the outputs of both individual cells and the whole corresponding horizontal and vertical feed lines is carried out. To verify the simulation results and to take the coupling effect into account, the radiation patterns of an isolated column, as well as those of three columns, are measured. In agreement with the design and with the simulation results, horizontal and vertical polarisation beams with a pointing angle mismatch of less than ±0.2° within the resonant frequency bandwidth of 2.75–2.95 GHz are achieved.

Compact dual polarized aperture coupled microstrip patch antenna for UWB RFID applications

Compact dual polarized aperture coupled microstrip patch antenna for UWB RFID applications

A Low-Profile Aperture-Coupled Microstrip Antenna With Enhanced Bandwidth Under Dual Resonance

A low-profile aperture-coupled microstrip patch antenna (MPA) using the TM10 and TM30 resonant modes to enhance the impedance bandwidth is proposed in this paper. Based on the cavity model for a square MPA, the TM10 and TM30 modes as well as both higher odd-order and even-order modes between them can be characterized. In order to combine the dual radiative resonant modes for a wide impedance bandwidth, a rectangular radiating patch with an aperture-coupled feeder is employed and theoretically investigated at first, aiming to demonstrate that all of the undesired modes between them can be removed effectively. After that, by loading the shorting pins properly underneath the patch, the resonant frequency of TM10 mode is shown to progressively turn up with slight effect on that of TM30 mode. As a result, these two radiative modes can be allocated in proximity to each other, resulting in a wide impedance bandwidth with a stable radiation pattern and the same far-field polarization. Moreover, the principal parameters of the MPA have been extensively studied in order to investigate the sensitivity in input impedance of the aperture-fed patch antenna. Finally, the proposed antenna is fabricated and measured. Simulated and measured results are found in good agreement with each other and illustrate that the antenna achieves a wide impedance bandwidth of about 15.2% in fraction or 2.32–2.70 GHz under $\vert \text{S}_{\mathrm {\mathbf {11}}}\vert dB, while keeping a low profile property with the height of 0.032 free-space wavelength. Besides, a stable gain varied from 3 to 6.8 dBi within the whole operating band is also obtained.