Design and performance of a microstrip reflectarray antenna

Microstrip reflectarray antennas present an alternative to conventional directive antennas in that they are flat, inexpensive, easy to install and manufacture, conformal to the mounting surface, easy to package, and they possess high power and beam steering capabilities. For the first time, a comprehensive, experimentally verified design procedure for the microstrip reflectarray is presented. In this design procedure, the microstrip reflectarray has been shown to be an effective linear array capable of beam switching and dual polarization. The design procedure also allows the array to be fed from a feed-horn offset at any given angle to the plane of the array. The design procedure is well suited for CAD programs     

宽带毫米波微带天线的设计与分析

根据微带天线的设计技术要求,介绍了微带天线带宽的影响因素。在矩形毫米波微带天线设计与分析的基础上,分别设计出 C 型和 W 型两种宽带毫米波开槽微带天线。利用仿真软件对3 种天线的输入回波损耗、驻波系数、相对带宽和方向性等技术参数进行仿真优化和比较分析。仿真与实验结果表明,3 种天线的设计均满足技术要求,C 型和 W 型开槽微带天线较矩形微带天线的相对带宽大幅提高,且具备良好的定向辐射特性。     

Ka-band reflectarray using ring elements

A simple ring structure to realise a Ka-band circularly polarised microstrip reflectarray is presented. With rotation techniques employed to focus the reflected wave at a focal point, a 0.5 m right-hand circularly polarised microstrip reflectarray is developed and tested at 31.75 GHz resulting in 50% aperture efficiency. The cross-polarisation levels measured are 40.7 dB down at broadside, showing the validity of the structure.     

微带反射阵天线的分析与设计

介绍了微带反射阵天线的基本原理,分析了天线设计中阵元单元尺寸和间隔的计算、相位延迟线的选择、基片厚度的选取、误差分析、仿真验证等,根据分析结果提出了低副瓣微带反射阵天线的设计方法。实例测试结果表明,反射阵天线的总体性能接近抛物面天线的性能,易于折叠、携带方便。     

双层微带反射阵单元特性研究

微带反射阵单元是组成微带反射阵的基本元素,其性能的好差直接影响整个阵列的性能。本文首先介绍了仿真微带反射阵单元反射场相位的等效波导法的基本原理;然后分析了双层贴片上下不同宽度比、不同介质层厚度的对反射场相位曲线及频带宽度的影响,并提出如何获得阵列最大频带宽度;最后研究了接地面开槽结构对反射阵单元反射场相位、幅值的影响,计算结果表明适当大小的槽结构能够提高反射场相位曲线的平坦度及增大反射场幅值。     

Investigations into a power-combining structure using areflectarray of dual-feed aperture-coupled microstrip patchantennas

This paper details an investigation of a power combiner that uses a reflectarray of dual-feed aperture-coupled microstrip patch antennas and a corporate-fed dual-polarized array as a signal distributing/combining device. In this configuration, elements of the reflectarray receive a linearly polarized wave and retransmit it with an orthogonal polarization using variable-length sections of microstrip lines connecting receive and transmit ports. By applying appropriate lengths of these delay lines, the array focuses the transmitted wave onto the feed array. The operation of the combiner is investigated for a small-size circular reflectarray for the cases of -3 dB, -6 dB and -10 dB edge illumination by the 2×2-element dual-polarized array     

Design of a dual frequency reflectarray using microstrip stackedpatches of variable size

A new stacked microstrip reflectarray, based on patches of variable size, is proposed for dual frequency operation. A progressive phase distribution is achieved for the reflected wave at both frequencies by adjusting the resonant length of the patches in each elementary cell of the reflectarray     

Full-Wave Analysis of Inside Cylindrical Microstrip Lines by Finite Element Method

In this paper, a full-wave analysis using finite element method is presented to investigate the dispersion characteristics of inside cylindrical microstrip lines, which are essential to the design of some conformal microstrip circuits in millimeter wave bands. Numerical results of frequency-dependent effective dielectric constants are given for different structural dimensions and dielectric constants of substrate. Some useful conclusions are derived for the design of the special conformal microstrip lines.     

一种渐变槽线作馈源的新型微带反射阵

提出了利用渐变槽线天线物理截面小的特点与变极化技术相结合的方法来改善微带反射阵馈源的遮挡效应,并设计了用于变极化微带反射阵馈源的渐变槽线天线及含37单元的微带反射阵。鉴于这些特点,该类天线在雷达、移动通信等领域具有潜在工程应用。文中给出了部分的理论分析和实例佐证。     

Computer-aided design for finlines and suspended-substrate microstrip lines

The computer-aided design of finlines and suspended-substrate microstrip lines are investigated. The numerical results of this paper show good agreement with those computed by other techniques for unilateral finlines and open suspended microstrip lines. The approach of this paper may be used to the computer-aided design of many other kinds of transmission lines and circuits for millimeter wave applications.     

基于两种单元贴片的毫米波平面反射阵列天线

针对单层介质单一贴片很难实现360°全域相位变化,文中提出了一种拥有环形贴片和环圆混合型贴片两种贴片组合结构的毫米波平面反射阵列天线,这种结构可以实现更为平滑的360°相位变化.利用这项技术,设计和分析了频率为94GHz的单层毫米波微带平面反射阵列天线,仿真计算验证了该方案的可行性.     

A Ka-band microstrip reflectarray with elements having variablerotation angles

This paper demonstrates a novel means of achieving cophasal far-field radiation for a circularly polarized microstrip reflectarray with elements having variable rotation angles. Two Ka-band half-meter microstrip reflectarrays have been fabricated and tested. Both are believed to be the electrically largest reflectarrays ever developed using microstrip patches. One, a conventional design, has identical square patches with variable-length microstrip phase-delay lines attached. The other has identical square patches with identical microstrip phase-delay lines but different element rotation angles. Both antennas demonstrated excellent performance with more than 55% aperture efficiencies, but the one with variable rotation angles resulted in better overall performance. A brief mathematical analysis is presented to validate this “rotational element” approach. With this approach, a means of scanning the main beam of the reflectarray over a wide angular region without any RF beamformer by using miniature or micromachined motors is viable     

Design of an Electronically Beam Scanning Reflectarray Using Aperture-Coupled Elements

The design of a C-band electronically beam scanning reflectarray is presented. The reconfigurable reflectarray element consists of a microstrip patch, printed on a flexible membrane substrate, aperture-coupled to a transmission line loaded with two varactor diodes. The designed element allows continuous tuning of the reflected signal's phase over a 360deg range with a maximum loss of 2.4 dB at 5.4 GHz. The measured results on a 30-element reflectarray breadboard show that by varying the bias voltages on each element the main beam can be steered to large angles, up to 40deg from broadside in the H-plane. A loss analysis of the proposed reflectarray is also presented     

双频宽带大型微带反射阵天线设计

微带反射阵天线在性能上最主要的缺陷就是窄带,一般情况下其带宽小于5%,对电大口径短焦距馈电时更窄。本文设计并制作出一种由L波段和C波段两个反射面天线组成的6m×2m薄膜双频微带反射阵天线,两个频段的天线共用一层膜面。对该天线的电性能进行了测试,测试结果表明:该天线两个频段的相对带宽均大于10%(副瓣电平≤-18dB)。该天线具有折叠、可展开的结构特征,可以在卫星或航天器上广泛应用。     

宽带缝隙堆叠贴片微带反射阵天线的研究

微带反射阵天线具有易折叠、易携带等特点,结合缝隙堆叠贴片（ASP）微带单元频带较宽的优势,能进一步展宽缝隙耦合反射阵的带宽。通过求解相位计算公式,得到反射阵表面相位分布。给出了ASP微带天线的设计参数、S参数曲线及对应ASP单元的反射相位曲线,用所设计单元组成225元反射阵模型,结果显示该模型中心频率最大增益为26.03dBi,1.5dB增益带宽为33.3%,在整个带宽内具有良好的工作性能。     

毫米波微带键合金丝互连模型的研究

本文应用神经网络方法、采用FDTD全波分析结果作为训练样本得到了毫米波微带键合金丝互连的参数模型.这个神经网络模型可以指导毫米波集成电路的设计,利用该模型可以得到不同拱高、微带间隙和频率时的电路散射参数.实验测试了键合金丝互连的散射参量并与神经网络模型的结果进行了比较分析.     

高性能Ka频段收发前端的研制

介绍了一种Ka频段收发前端的工作原理和工程研制结果。该收发前端采用四次谐波混频器、毫米波微带滤波器、多芯片混合集成等技术，具有高性能、小型化、高可靠性等优点，并在宽温度范围、振动、冲击等条件下，满足毫米波系统要求。     

Novel Broadband Reflectarray Antenna with Two-Type Elements for Millimeter-Wave Application

A novel broadband millimeter-wave microstrip reflectarray antenna with square-annular patches and combined patches has been presented, aiming to solve the problem of how to obtain a full 360° range of phase shifts for single-layer. The choice of these two-type elements can make the phase shift smoother and increased up to 360°, leading to broader bandwidth. Based on this technique, a single-layer microstrip reflectarray antenna operating at 94 GHz has been designed. The computed results demonstrate the agreement of the main beam steering with the design requirement, and a 1-dB gain bandwidth close to 10% is obtained. The simulation results verify the feasibility of this design.     

Mechanically controlled reflectarray antenna for beam switching and beam shaping in millimetre-wave applications

A novel method is proposed to shape or switch the radiating beam of a reflectarray antenna by slight displacement of its layers with respect to each other. A reflectarray, which is a quasi-periodic structure composed of microstrip patches loaded by slot elements, is used in this scheme. The required phase shift at each position on the reflectarray surface is obtained by varying the slot length on the ground plane. Several groups of slots are etched on the slot layer and each group corresponds to one and the same beam. Mechanical alignment of the slots that belong to a certain group with the patch leads to activation of the corresponding beam. This method was used to design a reflectarray antenna with three beams at /spl plusmn/30/spl deg/ and 0/spl deg/. Measurement results demonstrated the validity of the design procedure.     

A C/ka dual frequency dual Layer circularly polarized reflectarray antenna with microstrip ring elements

This paper reports a dual frequency dual layer circularly polarized reflectarray operating in the C and Ka bands. A 0.5-m right-hand circularly polarized planar reflectarray antenna is designed using microstrip ring elements of variable rotations to achieve a cophasal beam at broadside. The microstrip ring elements are more compact than the traditional reflectarray elements and can minimize blockage for the multilayer multifrequency applications. The highest efficiencies measured are 46% at 7.3 GHz and 38% at 31.75 GHz. The tested cross-polarization levels are -21 dB at 7.3 GHz and -29.2 dB at 31.75 GHz at the broadside direction. The tested results show that the designed ring element is suitable for both the single and dual layer applications with good bandwidth and circularly polarized performance.