Microstrip Array Research Articles

Adaptively Smart Wireless Power Transfer Using 2-Bit Programmable Metasurface

An adaptively smart wireless power transfer (WPT) system is proposed by using a 2-bit programmable metasurface (PMS), in which an indoor dynamic charging application scenario is described and near-field focused (NFF) technique is adopted to transmit wireless powers. Theoretical analyses of NFF PMS are presented to illustrate its WPT capabilities. To implement dynamic WPTs, digital phase-shift quantization of PMS element is investigated, indicating that 2-bit quantization scheme is a preferred solution. As experimental demonstrations, a 2-bit 12 × 12 PMS operating at 5.8 GHz is designed, fabricated, and tested. High-power focal spots that can be regulated to focus at different near-field positions are measured in an anechoic chamber. We conduct multiple WPT experiments by using the 2-bit PMS as the transmitter and a 4 × 4 microstrip array antenna as the receiver. Experimental results show that the proposed 2-bit PMS can continuously transmit the wireless powers to the receiver even though the target is moving, and the WPT efficiency is maintained over 9.1%, which has about 16.3 dB improvement at the end of the trajectory compared to the fixed NFF beam. This work is one of the first attempts to thoroughly examine the possibility of the dynamic WPTs using PMS, offering a brand-new manner for the adaptively smart WPT systems.

A Low-RCS and Wideband Circularly Polarized Array Antenna Co-Designed With a High-Performance AMC-FSS Radome

In this letter, we investigate a low radar cross-section (RCS) wideband circularly polarized microstrip array antenna co-designed with a high-performance artificial magnetic conductor and frequency selective surface (AMC-FSS) radome. Compared with the absorbent frequency selective radome-based antenna, the proposed co-designed antenna can achieve a relatively low gain loss in an extremely wide frequency range with wideband in-band and out-of-band RCS reduction, due to the introduction of a novel AMC-FSS radome which can achieve low insertion loss and wideband transmission by combining a double-layer miniaturized bandpass FSS and a single-layer chessboard AMC surface. We demonstrate the effectiveness of the proposed AMC-FSS radome and co-designed antenna through simulations and measurements. The results show that the gain deterioration of the co-designed antenna is only 0.42 dB at the central frequency of 4.8 GHz and less than 1 dB in the wide frequency band, ranging from 4.23 to 5.38 GHz with a relative bandwidth of 23.9%. At the same time, the monostatic RCS for a normal incidence is greatly reduced from 4 to 18 GHz.

Design and Analysis of MIMO Patch Antenna for 5G Wireless Communication Systems

In this work, the circular array microstrip patch antenna (MPA) design is proposed for the 5G wireless communication and the millimeter- wave frequency being utilized for this communication system to enhance the coverage area. Here, the Multi Input Multi Output feeding technique is utilized to improve the performance of the proposed design at a resonant frequency of 35 GHz with RT-Duroid 5880 material as substrate. It has 2.2 dielectric constant value and the thickness is 0.5mm.The simulation analysis has obtained the gain as 8.8dB and return loss as -41.9dB. Also, two MPA designs such as single element MPA and 2x2 rectangular array MPA are designed to validate the proposed antenna design. A comparative analysis has proved that the circular array MPA is preferable for the 5G wireless communication system compared to the other two designs such as single element MPA and 2x2 rectangular array MPA.

A Wideband High-Gain Microstrip Array Antenna Integrated with Frequency-Selective Surface for Sub-6 GHz 5G Applications.

This paper presents a wideband and high-gain rectangular microstrip array antenna with a new frequency-selective surface (FSS) designed as a reflector for the sub-6 5G applications. The proposed antenna is designed to meet the US Federal Communications Commission (FCC) standard for 5G in the mid-band (3.5–5 GHz) applications. The designed antenna configuration consists of 1 × 4 rectangular microstrip array antenna with an FSS reflector to produce a semi-stable high radiation gain. The modeled FSS delivered a wide stopband transmission coefficient from 3.3 to 5.6 GHz and promised a linearly declining phase over the mid-band frequencies. An equivalent circuit (EC) model is additionally performed to verify the transmission coefficient of the proposed FSS structure for wideband signal propagation. A low-cost FR-4 substrate material was used to fabricate the antenna prototype. The proposed wideband array antenna with an FSS reflector attained a bandwidth of 2.3 GHz within the operating frequency range of 3.5–5.8 GHz, with a fractional bandwidth of 51.12%. A high gain of 12.4 dBi was obtained at 4.1 GHz with an improvement of 4.4 dBi compared to the antenna alone. The gain variation was only 1.0 dBi during the entire mid-band. The total dimension of the fabricated antenna prototype is 10.32 λo × 4.25 λo ×1.295 λo at a resonance frequency of 4.5 GHz. These results make the presented antenna appropriate for 5G sub-6 GHz applications.

Conformal microstrip array antenna with the omnidirectional pattern for 5G applications

AbstractThis letter presents an omnidirectional conformal array microstrip patch antenna at 3.5 GHz band. The array of 1 2 elements are used as a radiating element and placed on the planar face of a regular six‐faced hexagonal structure connected with six faced feeding network. The feeding network consists of one three‐way power divider and two two‐way power dividers. These power dividers are serially connected to each other and form a six‐faced regular structure with 12 output ports. The response of the conformal antenna is verified experimentally. A measured reflection coefficient is well below dB and isolation between the output ports are −20 dB. The proposed omnidirectional conformal antenna is low‐cost, easy to fabricate, and suitable for an omnidirectional radiation pattern for 5G applications.

Mutual Coupling Compensation for Compact MIMO Radar

A calibration method to compensate for the mutual coupling and channel imbalance in a compact multi-input multi-output (MIMO) radar array based on turn table measurements is proposed. Two mutual coupling matrices, one for the transmit array and the other for the receive array, are used to model the relationship between the ideal manifold and the measured manifold. The practical factors such as the nonisotropic element pattern and the displacement of the array phase center are also taken into account. All the unknowns are determined by solving the nonlinear least-squares fitting problem iteratively. Using two coupling matrices consists of the mutual coupling mechanism in an MIMO array and has better calibration performance than using one matrix for the virtual array. It also reduces the dimension of the matrix and hence the computation load of calibration. Measurements by a microstrip array with two transmitters and four receivers are used to verify its effectiveness in angle estimation, beamforming, and superresolution of close targets.

2x2 Array Microstrip Patch Antenna Designing and Validation with Artificial Neural Networks

A novel and successful method for RF, microwave modelling, and antenna design has gained attention: computational modules based on neural networks. The behavior of active or passive components or circuits can be taught to neural networks. The design of a microstrip patch antenna utilizing an artificial neural network (ANN) is discussed in this research. Computer Simulation Technology (CST) is used to establish the antenna's size and characteristics in order to create a successful ANN model. The feed-forward back-propagation neural network and Levenberg Marquardt optimization algorithm are used to model the antenna design. High-Frequency Structure Simulator (HFSS) software, operating at 2.4 GHz, is used to build the initial microstrip patch (ISM band).A 2.4GHz operating frequency is used to create a 2*2 microstrip planar array. A variety of neural networks are evaluated and trained to produce the most ideal results after generating and modelling discoveries using HFSS simulation software and the Finite Difference Time Domain (FTDT) approach. In this research, neural networks are utilized. In order to identify the most ideal solution, optimization is performed using a radial basis function neural network (RBF NN) and a feed-forward backpropagation approach.

Electronically beam switched conformal microstrip array antenna for 5G applications

This article presents an electronically beam-switching conformal microstrip array antenna for 5G applications. The 1 × 2 array microstrip antenna is used as a radiating element. They are placed on a hexagonal shape-holding structure to form the conformal geometry. The radiating elements are excited with a six-faced feeding network. It consists of one 3-way power divider and two 2-way power dividers. These power dividers (PDs) are serially connected and formed a six-faced regular structure with 12 output ports. To obtain the beam switching mechanism, the uniform PD is then loaded with RF switched PD. Six angular separation beams (Sectors I–VI) are obtained (each 60°) with RF switches (1 SP3T and 3 SPDT). The response of the feed network is verified experimentally with a conformal array structure. The impedance bandwidth is well below −10 dB and measured for all switched sectors. The measured isolation among different output ports of the device is below −20 dB. The simple microstrip design technique makes the device suitable for beam switching in a large array configuration for 5G applications.

Disain Antena Mikrostrip Array Tiga Band untuk Aplikasi WiFi dan WiMax

In this research, a 1x2 circular patch microstrip array antenna with feeding line is made which can be used on WiFi and WiMax which work at frequencies of 2.4, 3.7 and 5.8 GHz. This antenna design uses Ansoft HFSS software. Where the simulation results at a frequency of 2.4 GHz obtained a return loss value of -22.28 dB, -19.03 dB at 3.7 GHz and -14.94 dB for 5.8 GHz, VSWR 1.17 for 2.4 GHz, 1.25 at 3, 7 GHz and 1.43 for 5.8 GHz.Gain is 1 dB and directivity is 2,33 dB. The simulation results show that the parameters meet the minimum standard of the performance of an antenna, the Return Loss (RL)<-10 dB for 5.8 GHz, VSWR<2. Therefore, this antenna is suitable for use for WIFI and WLAN applications

Omnidirectional conformal microstrip array antenna with electronically beam switching capabilities for 5G applications

This article presents an omnidirectional and electronically beam switching conformal microstrip array antenna at 3.5 GHz frequency for 5G applications. The 1×2 array microstrip antenna is used as a radiating element. It is placed on a hexagonal shape-holding structure to form the conformal geometry. The radiating elements are excited by a six-faced feeding network. It consists of one 3-way power divider and two 2-way power dividers. These power dividers are serially connected and form a six-faced regular structure with 12 output ports. The output ports of the uniform power divider feed network are connected to the conformal array and provide the omnidirectional radiation pattern. To obtain the beam switching mechanism, the uniform power divider is then loaded with an RF switched power divider and connected to the conformal array. Six angular separation beams (Sector I to VI) are obtained (60°) with RF switches. The response of the feed network along with the radiating element is verified experimentally. The impedance bandwidth is well below <−10 dB and measured isolation among different output ports are below −20 dB. The simple microstrip design technique makes the antenna suitable for omnidirectional and beam switching in a large array configuration for 5G applications.

Design of a Transparent System for Mutual Coupling Reduction of Microstrip Array Antennas with Confined Water

Herein, a new method for minimizing mutual coupling of an antenna array with confined water is proposed. In multiantenna systems, mutual coupling reduction is needed to sustain array signal processing efficiency. There are currently a variety of ways to suppress coupling, including defected ground, electromagnetic (EM) bandgaps, and advanced structures. The water absorption characteristic is devised in this innovative approach to minimize mutual coupling without a permanent alteration in the structure. Surface current between two antennas is cancelled using permittivity and water depth in a new configuration. A plexi‐glass confined water is added between the propagating elements to achieve this aim. The rectangular microstrip patch of transparent conducting components serves as the antenna array. Using scattering theories, numerical EM calculations, and anechoic chamber tests, the suggested technique shows a 15 dB decrease in coupling at center frequency (7 GHz). Other propagating functions have also been improved. The suggested framework can be used in multifunction communication networks, aerial vehicle antennas, solar panels, and naval communications because of its optical transparency.

A Single-Layer Dual-Band Dual-Sense Circularly Polarized Patch Antenna Array With Small Frequency Ratio

A planar dual-band dual-sense circularly polarized (CP) microstrip array is proposed. This array is implemented on a single-layer substrate and easily extended to the design of a larger array. A new antenna element is exploited by symmetrically placing the nonradiative resonators on four side edges of a square patch. A quantitative design method is proposed based on the equivalent circuit model of the antenna element. For given two operating frequencies, the required design parameters of the patch and nonradiative resonators can be calculated. Theoretical magnitude ratio and phase difference responses of two far-field components, as well as axial ratio responses under different parameters, are presented to reveal the characteristics of the antenna element. Full-wave simulation results are found to agree well with the theoretical ones. To further validate the effectiveness, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2 \times 2$ </tex-math></inline-formula> element dual-band dual-sense CP array operating at 2.40 and 2.68 GHz is designed, fabricated, and measured, where a small frequency ratio of 1.117 is achieved. The measured realized gains in the low and high bands are 11.7 and 11.8 dBi, respectively, which are approximately equal.

On Microstrip Array Antenna with Enhanced Bandwidth and Gain Using Modified Ant Lion Optimization for X-Band Applications

This article furnishes the design and analysis of three concentric circular array antennas (CCAAs) of point sources and a linear microstrip patch array antenna (LMPAA) employing a newly developed hybrid optimization algorithm, the modified ant lion optimization (MALO). The optimum CCAAs employing MALO offer better radiation patterns in terms of the reduction in peak side lobe level, null depths, first null beam width, and directivity considering the same apertures, compared to some other popular optimization algorithms available in the literature. In the other hand, the LMPAA with optimized rectangular ring shaped slots in its ground plane using MALO enhances its bandwidth (BW), gain, and directivity. A prototype of the proposed LMPAA is fabricated, which offers measured values of BW, gain, directivity, and radiation efficiency of 907.1 MHz, 10.26 dBi, 12.19 dB, and 84.16%, respectively. The LMPAA is compared with some previously available designs in the literature to highlight its significance and hence to validate the process of employing optimization algorithms in design and analysis of real antennas.

Design and Fabrication of Broad-Beam Microstrip Antenna Using Parasitic Patches and Cavity-Backed Slot Coupling

The adjusting parasitic patch size technique for the broad-beam microstrip antenna array using the cavity-backed slot coupling is presented. The phase of each element of the microstrip array has been designed to emulate the reflection of waves on the surface of parabolic backscattering. In order to increase the efficiency of this array antenna, the back-slot cavity with an exciting probe will be employed for coupling the electromagnetic waves to the back of this array. The proper sizes and locations of patches and the optimized position of the cavity have been investigated by the Computer Science Technology (CST) Microwave Studio. The gain, the radiation pattern, the bandwidth, and the return loss are extensively analyzed. The fabricated antenna has the return loss of −22.39 dB, the bandwidth of 47 MHz (4.975–5.022 GHz), and the maximum directive gain of 5.6 dB at 5 GHz, and it can produce a wide beam width (half-power beam width around 130°). The antenna could be applied for wide applications in the wireless communications system. In particular, this realizing antenna covers the low earth orbit (LEO) satellite beam.

Design and simulation of dual-band rectangular microstrip patch array antenna for millimeter-wave

Microstrip array antennas are essentially for radar and communications systems. They are used to get a needed pattern that cannot be realized with a single element. This paper aims to design and simulate of rectangular microstrip patch array antenna 1 patch (1×1), 2 patches (1×2), and 4 patches (1×4) and improve the performance results. The proposed antenna is simulated by using electromagnetic simulation, computer software technology Microwave studio (CST) printed on Rogers RT5880 (lossy) substrate with dielectric constant 2.2, 0.0009 loss tangent, and thickness 0.1 mm. The simulation results show that the small patch antenna size (1.57 mm × 2 mm) for three designs works at dual bandwidth. The major target of this work is to accomplish an unusual directivity with improved gain for three antenna array designs.

Enhanced beamforming techniques for cylindrical-substrate microstrip array antennas

PurposeA class of robust and efficient beamforming methods is developed in this paper for the optimised design of realistic microstrip antennas on arbitrarily curved substrates. More specifically, this paper aims to focus on the formulation of an effective and computationally light beamforming algorithm and its implementation on a novel realistic cylindrical-substrate microstrip array antenna with significantly decreased size, wideband operation and enhanced radiation characteristics.Design/methodology/approachThe proposed multi-parametric schemes introduce an efficient null-steering concept, which drastically annihilates the undesired beamformer waveform artefacts, while retaining the real output signal undistorted. In particular, the key objective is the accurate calculation of the appropriate complex feeding weights, required to set nulls along the propagation directions of the unwanted signals and a maximum towards the propagation direction of the desired incoming signal. The featured technique, combined with a modified finite element method, is applied to the design of a new family of cylindrical-substrate microstrip array antennas.FindingsNumerical results, mainly concerning customisable three-dimensional radiation patterns and attributes, certify the merits of the algorithm and its limited system demands. The introduced beamforming algorithms are applied to a variety of different inputs (desired radiation patterns), which indicate that the designed cylindrical-substrate antenna overwhelms existing designs in terms of computational cost for the beamforming algorithm, while retaining acceptable values for radiation characteristics, such as gain, directivity and side-lobe suppression. In this manner, the effectiveness of the prior methodology and the benefits of this newly shaped array antenna are comprehensively revealed and substantiated.Originality/valueRigorous beamforming techniques in conjunction with a class of contemporary array antennas are developed for potential use in high-end communication systems, such as 5G configurations. The proposed cylindrical-shaped structures are systematically designed, with an emphasis on space efficiency and wideband radiation effectiveness to offer fully adjustable setups. To this aim, the cylindrical-substrate microstrip antenna, because of its inherent azimuthal symmetry and confined overall dimensions, provides reliable operation and promising performance.

The Size Effect on Contact Angles and Dynamic Behaviors of Droplets on Microcolumn and Microstrip Array Surfaces

The hydrophobicity of biomimetic hydrophobic surfaces exhibits a correlation with droplet relative dimension. Nevertheless, the droplet relative dimension‐dependent wettability, contact angles, dynamic droplet bouncing behaviors need to be further investigated. This article focuses on the size effect of droplet relative dimension on the contact angles and dynamic behaviors of regular microcolumn and microstrip array surfaces, which were directly machined by low‐speed wire electrical discharge machining (WEDM‐LS). Specifically, the contact angles are measured with droplet relative dimension in a range from 29.8 to 298 on various structured surfaces. The dynamic droplet bouncing tests are based on a coincident falling height of 10 mm. The period time is also gradually shortened with the decreasing of droplet relative dimension, which indicated that the droplets with relatively larger relative dimensions are more difficult to overcome the adhesion of arrayed structures. Meanwhile, when the droplet relative dimension exceeded a critical value, the droplet failed to separate from the substrate due to the interface adhesion and the period time would be also shortened which attributed to less time consumption for the insufficient capillary force compared with the gravity.

Compact FIN defected ground structure for improved cross polarisation in array antenna

ABSTRACT In this article, a 2 × 2 microstrip array antenna integrated with FIN defected ground structure (DGS) is investigated, which is designed for 3.24 GHz band operation. The FIN-DGS has been etched from the ground plane in the H-plane direction between two contiguous elements in a symmetric manner. Therefore, it suppresses the cross-polarisation (XP) radiation in the antenna without affecting its co-polarisation (CP) radiation characteristics. A proposed antenna has been designed and experimentally verified and shows <35 dB XP (±50º) radiation around boresight of the radiating elements in the H-plane with 10.7 dBi gain. The variation of XP fields has been investigated using the modal field distribution. The designed antenna provides a wide range of applications in adaptive arrays and space antennas, where 3D coverage with decreased XP values is the primary constraint.

High Q Dielectric Titanium Tellurite Thick Films on Alumina Substrates for High Frequency Telecommunications

The vital role of high-quality-factor (Q) high-frequency (f) dielectric resonators in the growing microwave telecommunication, satellite broadcasting and intelligent transport systems has long motivated the search for new, small size, and lightweight integrated components and packages, prepared by low cost and sustainable processes. One approach is replacing the currently used bulk ceramic dielectrics by thick films of low-sintering-temperature dielectrics fabricated by affordable processes. Here we demonstrate the fabrication of high-Q TiTe3O8 thick films directly on low loss Al2O3 substrates by electrophoretic deposition using sacrificial carbon layer. Nineteen-micrometre-thick TiTe3O8 films on Al2O3 sintered at 700 °C are found to have a relative permittivity εr of 32 and Q × f > 21,000 GHz. Being thus able to measure and provide for the first time the microwave dielectric properties of these films, our results suggest that TiTe3O8 films on Al2O3 substrates are suitable for microlayer microstrip array applications.

Mutual Decoupling for Massive MIMO Antenna Arrays by Using Triple-Layer Meta-Surface

The high isolation massive antenna arrays are the key devices in the base station of the future wireless communication systems. The challenge for the array application is how to reduce the coupling among the array elements. This paper introduces a new decoupling method for massive MIMO arrays with an innerelement distance of around half wavelength by using a triple-layer metasurface (TMS). The TMS comprises three identical surfaces. The waves reflected from the bottom metasurface (MS) and top two-layer MS have the same amplitudes and the opposite phases, which are canceled with each other. An example of 4×4 dualpolarized wideband microstrip array with a TMS is proposed to verify the decoupling method. The simulation and measurement show that the TMS can help reduce the coupling among the array elements to less than -24 dB in both the co-polarization and cross-polarization directions within 4.23-4.82 GHz. In the meanwhile, the radiation characteristics of the arrays with and without TMS are almost unchanged.