Design Of Microstrip Antenna Array Research Articles

Design of Microstrip Antenna Arrays with Rotated Elements Using Wilkinson Power Dividers for 5 G Customer Premise Equipment Applications

Microstrip antenna arrays are proposed in this paper for the customer premise equipment (CPE) applications in the frequency range 1 (FR1) of the 5th generation (5 G) mobile networks. The proposed antenna arrays consist of three FR4 substrates. Antenna elements and feeding networks are optimized separately through parameter studies and then combined to form the proposed antenna arrays. Bandwidth-enhancing parasitic elements on the top substrate are broadside coupled to the microstrip antennas in the middle substrate, which are probe-fed by the microstrip feeding network using Wilkinson power dividers realized in the bottom substrate through the ground plane and the stud supporting air layer between the lower two substrates. Two antenna arrays, with four and eight antenna elements, are proposed for different gain specifications, 10 dBi and 12 dBi, respectively. Bandwidths of 10-dB return loss for both arrays fully covered the 5 G n78 frequency band (3.3–3.8 GHz). 20 dB isolation between antenna elements can also be achieved using the proposed layouts with rotated elements. The dimensions, radiation gain, and efficiency of the proposed antenna units, four-element array, and eight-element array are 65 × 65 × 11.4, 115 × 115 × 11.4, and 115 × 215 × 11.4 mm3, 6.2, 10.5, and 13 dBi, 74%, 56%, and 50%, respectively. The proposed antenna arrays exhibit the advantages of simple, low-cost, low-profile, and high-gain characteristics, which is potentially applicable to 5 G CPE outdoor unit (ODU)-related devices.

Development of a novel optimization algorithm for a microstrip patch antenna array

<span>Microstrip patch antennas are typically used because they have a low profile and cost. The main theme of this study is to present a novel 2×2 microstrip antenna array design using rough set theory. In designing the 2×2 microstrip antenna array, an FR4 dielectric substrate was used to improve the performance. The rough set theory was used to optimize the microstrip antenna parameters. The FR4 dielectric substrate compared better to the microstrip patch antenna array wherein no substrate was used. The antenna with no substrate used had the energy that is radiating underneath which contributed to the sidelobes of the radiation pattern whereas the use of the substrate reduced the energy radiated at the substrate. Furthermore, the gains of the two were also simultaneously evaluated and it showed that the microstrip antenna array with the dielectric substrate had better gain than the one without. This 2×2 microstrip array antenna design may be used for applications such as mobile communications since it is small in size and performs well.</span>

Оценка влияния формы простого микрополоскового излучателя на его широкополосность

Microstrip antennas are one of the most common types of antennas for mobile objects. Compactness, lightness and conformity make their use convenient and in fact the only solution for the rapidly developing industry of wire-less telecommunications. The key disadvantage of such antennas is their narrow bandwidth inherent in all resona-tor type antennas, microstrip antennas being a particular case. Basically, the narrowband nature of such antennas is due to a pronounced frequency dependence of the input impedance, as a result of which a satisfactory quality of natural matching can be achieved in a frequency band measured in units of percent. The paper considers mi-crostrip radiators of simple geometry: rectangular, square, rhombic, triangular, round, elliptical, located on a sub-strate of fixed geometry with the same dielectric. For each shape of the strip geometry, numerical optimization of the strip dimensions and the position of the excitation point is performed in order to obtain the maximum bandwidth of natural matching in VSWR of no more than 2 when con-nected to a 50-ohm feeder. The frequency of 2 GHz was chosen as the central frequency in numerical studies. Cal-culations of the directional characteristics of the most successful variants of microstrip radiators within the matching band are given. It is shown that for a given ge-ometry and parameters of filling the substrate, the most broadband is a microstrip elliptical radiator, the matching bandwidth of which is from 1900 to 2100 MHz, i.e. +/- 5% of the center frequency. The results obtained can be use-ful both in the design of microstrip antenna arrays and in the construction of microstrip multiband antennas, which is especially important for new generation mobile com-munication systems.

Improved fully-connected neural network approach for decoupling microstrip antenna array design

This article presents an improved fully-connected neural network (FCNN) approach to design a decoupling microstrip antenna array. Through combing the advantage of waveguide (WG) structure and complementary double split ring resonator (CDSRRs), a novel decoupling structure is proposed, which can effectively suppress the mutual coupling between two close patches, and our improved FCNN can predict the geometry of the proposed antenna array to obtain the desired isolation. To demonstrate the validity and reliability of this method, the improved FCNN approach is used to predict the geometric parameters of the proposed antenna array when the distance of patch is reduced to 8 mm, 7mm and 6 mm. The measurement results of the predicted antenna arrays show that, their corresponding isolations are 51.16 dB, 41.99 dB and 42.43 dB respectively. The improved FCNN approach is proved to obtain the optimal isolation with lower computational complexity.

Compact Ultra-Wideband Series-Feed Microstrip Antenna Arrays for IoT Communications

Modern communication systems require high bandwidth to meet the needs of the huge number of sensors and the growing amount of data consumed, and an exponential growth is expected in the future with the integration of internet of things networks. Spectrum regions in the millimeter waves have aroused new interests, mainly because of the contiguous bands available to meet these needs. In return, and to combat the high losses of propagation in these frequencies, higher gain antennas are needed. This paper describes the use of a logarithmic architecture in the design of microstrip antenna arrays, creating structures with high gain and ultra-wide bandwidth. Three different solutions are presented with five, seven, and nine elements, reaching about 25%, 30%, and 44% of bandwidth, achieving ultra-wideband behavior, efficient and with a compact structure operating at frequencies in around 28 GHz.

Novel design of microstrip antenna array with low scattering performance

In this paper, the idea of electromagnetic surface (EMS) is introduced into the design of microstrip antenna array. The antenna element proposed in this paper is treated as an EMS element, whose reflection characteristics are taken into consideration in the process of antenna array design. Firstly, a rectangular patch antenna element is designed. Then, by cutting arc-shaped structure into a rectangular patch, another element is created to generate 180° ± 30° effective phase difference compared with original antenna element. As a consequence, 180° ± 30° effective phase difference is obtained from 5.5 GHz to 6.9 GHz for the <i>y</i>-polarized incidence. Meanwhile, for the <i>x</i>-polarized incidence, each of the two elements possesses high absorptivity over the operating frequency as a result of matching load. Besides, the two elements work in the same resonant mode and the same resonant frequency band when treated as radiators. In order to further explain the consistency in radiation and difference in reflection between the two structures, current distribution at 5.8 GHz is investigated in terms of radiation and reflection. Then, the two elements are arranged into a chessboard array to achieve the low scattering performance based on phase cancellation principle under the <i>y</i>-polarized incidence. Based on the absorption principle, the matching load is added to improve the scattering performance of the composite antenna array with the <i>x</i>-polarized incidence. Simultaneously, the proposed antenna array maintains good radiation characteristics due to the consistency between the radiation performances of the two elements. The corresponding antenna array is fabricated and tested. Simulated and measured results prove that the proposed antenna array also achieves good radiation performance. And a 6 dB radar cross section reduction is obtained from 5.6 to 6.2 GHz under the <i>x</i> polarization and from 5.5 to 7.0 GHz under the <i>y</i> polarization for the normal incident wave, implying 10.1% and 24% in relative bandwidth, respectively. In-band reflection suppression in the specular direction is demonstrated for an incident angle of 30° under both polarizations. The measured results are in good agreement with the simulated ones. Additionally, the approach proposed in this paper offers an effective way to deal with the confliction between radiation and scattering performance, and can also be applied to other kinds of antenna arrays.

A new design of microstrip antenna array for microwave power transmission

AbstractAn improved method used to design high transmission efficiency microwave power transmission (MPT) antenna array is proposed in this article. In this method, the constraint of the transmitting element arrangement is removed by defining the power transmission efficiency different from previous works, and the coupling between transmitting elements is included completely. Two 4 × 4 antenna arrays working at 5.8 GHz are designed and fabricated to verify it. These two arrays are used in two MPT systems, in each system the transmitting array and receiving array have the same geometry. The measured transmission efficiencies of antenna array 1 and array 2 are 65% and 58% when the transmission distances are 10 cm and 20 cm, respectively.

Design of Microstrip Antenna Array with Suppressed Back Lobe

A practical procedure to reduce the back lobe level of microstrip antenna arrays is presented in this paper. The novel concept consists in the design of the radiators asymmetrically positioned with respect to the ground plane. In order to validate this technique, a four-element linearly-polarized array is designed in the HFSS software and a prototype is manufactured. Furthermore, the design of beamforming circuit to achieve broadside radiation and -20 dB side lobe level is detailed. Very good agreement between simulated and experimental results is obtained. Although the technique is presented for linearly polarized arrays, it is general and can also be applied in the circularly polarized ones.

5 by 5 Microstrip Antenna Array Design by Multiobjective Differential Evolution based on Fuzzy Performance Feedback

Differential evolution is often regarded as one of the most efficient evolutionary algorithms to tackle multiobjective optimization problems. The key to success of any multiobjective evolutionary algorithms (MOEAs) is maintaining a delicate balance between exploration and exploitation throughout the evolution process. In this paper, the authors develop an Improved version of the Fuzzy-based Multiobjective Differential Evolution (IFMDE) that exploits performance metrics, specifically hypervolume, spacing, and maximum spread, to measure the state of the evolution progress. They apply the fuzzy inference rules, derived from domain knowledge, to these metrics in order to dynamically adjust the associated control parameters of a chosen mutation and crossover strategy used in this algorithm. One mutation parameter controls the degree of greedy or exploitation, while another regulates the degree of diversity or exploration of the reproduction phase. On the other hand, crossover rate controls the fraction of trial vector elements inherited from the mutant vectors. In doing so collectively, the authors can appropriately adjust the degree of exploration and exploitation through performance feedback. A 5 by 5 microstrip antenna array design problem is formulated as a three-objective optimization problem. The proposed IFMDE is applied to tackle this problem under real-world complications. Since the objective evaluations of a 5 by 5 microstrip antenna array are computationally very expensive, a radial basis function neural network is trained as a surrogate model for the fitness function approximations. The experimental results demonstrate the ability of IFMDE that it can find not only one, but a set of Pareto optimal solutions, specifically in terms of side lobe level and reflection coefficient. These multiple Pareto-optimal configurations can then be chosen from by a decision maker given dynamic operating environments, constraints and uncertainties.

Rapid design of microstrip antenna arrays by means of surrogate‐based optimisation

A technique for rapid simulation driven design of planar microstrip antenna arrays is introduced. It exploits the surrogate-based optimisation paradigm and variable-fidelity electromagnetic (EM) simulations. The design process includes radiation pattern optimisation and matching. Two low-fidelity models are utilised: a coarse-mesh EM model of the entire array and a model of the array based on the simulated single element radiation response combined with the array factor. Both models, after suitable correction, guide the optimisation process towards the optimum of the antenna array high-fidelity model. Design optimisation of a 5 × 5 and 7 × 7 microstrip antenna arrays is conducted and described to demonstrate operation as well as efficiency of the proposed technique. The computational cost of optimised designs is equivalent to a few high-fidelity simulations of the entire array despite a large number of design variables.

C波段携轨道角动量螺旋波微带阵天线设计

C波段携轨道角动量螺旋波微带阵天线设计

Comparison of Compact EBG Structures on the Mutual Coupling Reduction of Antenna Arrays

Mutual coupling is a critical issue in compact array design and reducing this is one of the main efforts in Microstrip antenna array design. Periodic structures can help in this situation by suppressing surface wave propagation in a given frequency range. The purpose of this work is to show the viability of using 2D EBG structures to this aim. This paper presents a double element Microstrip antenna array inserted with the EBG structures like conventional mushroom, Jerusalem cross slot and slot loaded EBGs around 5-6 GHz. The performances are compared for mutual coupling reduction. Simulated results verify the improvement in performance of the antenna array compared to the array antenna without EBG. The slot loaded EBG is found to be good showing a 5.8dB mutual coupling reduction.

COUPLING REDUCTION OF ANTENNA ARRAY ELEMENTS USING SMALL INTERDIGITAL CAPACITOR LOADED SLOTS

Small size capacitor loaded ground plane slots are used to reduce the mutual coupling between elements in a microstrip antenna array design. The proposed compact slots are inserted between the adjacent E-plane coupled elements in the array to limit the propagation of surface waves between the elements of the array. In order to validate the feasibility of the proposed structure, a two-element array with 0.5‚o distance between centers of two patches is designed, fabricated, and measured. The measured results show a reduction in mutual coupling of 17dB obtained between elements at the operation frequency.

EFFECT ON RESONANT FREQUENCY FOR E-PLANE MUTUALLY COUPLED MICROSTRIP ANTENNAS

The resonant frequency of a microstrip patch (rectangular, square, and circular) changes as soon as an identical patch is brought closer than 0.2λ. Closed form expressions are presented for the E-plane coupled configuration from which this altered resonant frequency may be easily computed. These expressions may be readily used in the computer aided design of microstrip antenna arrays.

Design of an S∕X dual-band dual-polarised microstrip antenna array for SAR applications

A novel design of dual-band dual-polarised microstrip antenna arrays for synthetic aperture radar applications with a frequency ratio of about 1:3 is presented. Stacked microstrip dipoles and square patches are used as the radiating elements at S- and X-bands, respectively. The microstrip dipoles are proximately coupled and the square patches are probe-fed. Experimental data show good agreement between simulated and measured results. The measured impedance bandwidth (VSWR≤2) the prototype array reaches 8.9% and 17% for S- and X-bands, respectively, and the measured isolation between polarisations for both bands are better than −20 dB. The measured crosspolarisation level is ≤−26 dB for the S-band and ≤−31 dB for the X-band. The work verifies the practicability of the dual-band dual-polarised microstrip antenna array design, using the combination of microstrip dipoles and patches, and good bandwidth and isolation performance of the prototype array has been achieved.

A novel low mutual coupling microstrip antenna array design using defected ground structure

Defected ground structures (DGS) have been developed to improve characteristics of many microwave devices. In this paper, using FDTD method, effect of DGS to mutual coupling reduction of a two-element microstrip antenna array is investigated. The proposed DGS antenna is compared to other techniques and is shown to have an exceptionally lower mutual coupling between two E-plane coupled elements. Impact of the designed DGS on higher-order modes and radiation pattern of the antenna array is also examined.

Resonant frequency of a microstrip patch in the vicinity of an identical radiator

The resonant frequency of a microstrip patch (rectangular, square, and circular) changes as soon as an identical patch is brought closer than 0.2λ to it. Closed-form expressions are presented for the H-plane-coupled configuration (the two adjacent patches are excited by same phase excitation) from which this altered resonant frequency may be easily computed. From the same expression the resonant frequency of an isolated patch antenna may also be calculated. A procedure utilizing these closed-form expressions for the design of microstrip patch antennas which will resonate at the desired frequency is also outlined. These expressions may be readily used in the computer-aided design of microstrip antenna arrays. © 1996 John Wiley & Sons, Inc.

Resonant frequency of a microstrip patch in the vicinity of an identical radiator

The resonant frequency of a microstrip patch (rectangular, square, and circular) changes as soon as an identical patch is brought closer than 0.2λ to it. Closed-form expressions are presented for the H-plane-coupled configuration (the two adjacent patches are excited by same phase excitation) from which this altered resonant frequency may be easily computed. From the same expression the resonant frequency of an isolated patch antenna may also be calculated. A procedure utilizing these closed-form expressions for the design of microstrip patch antennas which will resonate at the desired frequency is also outlined. These expressions may be readily used in the computer-aided design of microstrip antenna arrays. © 1996 John Wiley & Sons, Inc.

Use of the FDTD method in the design of microstrip antenna arrays

AbstractThe finite‐difference time‐domain (FDTD) method is a widely used numerical technique for computer‐aided design (CAD) of printed antennas and arrays. This technique can accurately predict performance characteristics of complex microstrip antennas, including the effects of parasitic elements and aperture‐coupled feeds. In the case of arrays, mutual coupling effects between closely packed elements can also be modeled. This article will examine the advantages and limitations of the FDTD method for CAD of microstrip arrays. Calculated results are compared with experiment for a 3‐patch coplanar parasitic patch array.