Design and performance of a microstrip reflectarray antenna
TL;DR: In this design procedure, the microstrip reflectarray has been shown to be an effective linear array capable of beam switching and dual polarization.
Abstract: 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. >
Citations
More filters
TL;DR: In this article, a periodic surface texture is used to alter the electromagnetic properties of a metal ground plane by covering the surface with varactor diodes, and a tunable impedance surface is built, in which an applied bias voltage controls the resonance frequency and the reflection phase.
Abstract: By covering a metal ground plane with a periodic surface texture, we can alter its electromagnetic properties. The impedance of this metasurface can be modeled as a parallel resonant circuit, with sheet inductance L, and sheet capacitance C. The reflection phase varies with frequency from +/spl pi/ to -/spl pi/, and crosses through 0 at the LC resonance frequency, where the surface behaves as an artificial magnetic conductor. By incorporating varactor diodes into the texture, we have built a tunable impedance surface, in which an applied bias voltage controls the resonance frequency, and the reflection phase. We can program the surface to create a tunable phase gradient, which can electronically steer a reflected beam over +/- 40/spl deg/ in two dimensions, for both polarizations. We have also found that this type of resonant surface texture can provide greater bandwidth than conventional reflectarray structures. This new electronically steerable reflector offers a low-cost alternative to a conventional phased array.
702 citations
TL;DR: In this paper, a multilayer reflectarray composed of two stacked arrays with rectangular patches of variable size is demonstrated, and a progressive phase distribution on the reflector surface is achieved by adjusting the dimensions of the patches.
Abstract: A multilayer reflectarray composed of two stacked arrays with rectangular patches of variable size is demonstrated. A progressive phase distribution on the reflector surface is achieved by adjusting the dimensions of the patches. The phase of the reflection coefficient at each element is computed by the method of moments in the spectral domain, assuming local periodicity. A technique is presented for the design of dual polarization reflectarrays that yields all the dimensions for the photo-etching mask. A prototype has been design, built and measured, and a superior bandwidth performance has been verified, compared to conventional single layer reflectarrays.
613 citations
TL;DR: In this paper, an electronically tunable reflectarray based on elements tuned using varactor diodes is presented, which accurately predicts the scattering characteristics of the unit cell as compared to experimental measurements.
Abstract: The reflectarray has significant promise in applications requiring high-gain, low-profile reflectors. Recent advances in tuning technology have raised the possibility of realizing electronically tunable reflectarrays, which can dynamically adjust their radiation patterns. This paper presents an electronically tunable reflectarray based on elements tuned using varactor diodes. Modeling approaches based on an equivalent circuit representation and computational electromagnetics simulations are presented. Both techniques accurately predict the scattering characteristics of the unit cell as compared to experimental measurements. The development of a unit cell with over 320omicron of phase agility at 5.5 GHz is discussed. Finally, a 70-element electronically tunable reflectarray prototype operating at 5.8 GHz is presented. Radiation pattern measurements with the reflectarray demonstrate its dynamic beam-forming characteristics. Measurements of the gain of the reflectarray correlate well with theoretical expectations.
273 citations
Cites methods from "Design and performance of a microst..."
...antennas have been proposed that use RF/MEMS switches [15], [16], tunable MEMS patches [22], and motors to move dielectric components [18], to achieve the desired effect....
[...]
TL;DR: In this paper, a reconfigurable microwave surface that performs as a new kind of beam steering reflector is described. The surface is textured with an array of tiny resonators, which provide a frequency-dependent surface impedance.
Abstract: We describe a reconfigurable microwave surface that performs as a new kind of beam steering reflector. The surface is textured with an array of tiny resonators, which provide a frequency-dependent surface impedance. By tuning the individual resonators, the surface impedance, and thus the reflection coefficient phase, can be varied as a function of position across the reflector. Using a reflection phase gradient, the surface can steer a reflected beam. As an example, we have built a simple mechanically tuned surface in which physical motion of only 1/100 wavelength generates a sufficient phase gradient to steer a reflected beam by /spl plusmn/16 degrees. To steer to greater angles, the surface can be configured as an artificial microwave grating, capable of /spl plusmn/38 degrees of beam steering. The concept of the tunable impedance surface demonstrated here can be extended to electrically controlled structures, which would permit more elaborate reflection phase patterns, and provide more capabilities, such as the ability to focus or steer multiple beams.
154 citations
TL;DR: In this article, 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.
Abstract: 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.
150 citations
Cites methods from "Design and performance of a microst..."
...The preferred phasing methods depend on the array element and the type of polarization [1], [4]–[7]....
[...]
References
More filters
Book•
01 Jan 1982
TL;DR: The most up-to-date resource available on antenna theory and design as mentioned in this paper provides an extended coverage of ABET design procedures and equations making meeting ABET requirements easy and preparing readers for authentic situations in industry.
Abstract: The most-up-to-date resource available on antenna theory and design Expanded coverage of design procedures and equations makes meeting ABET design requirements easy and prepares readers for authentic situations in industry New coverage of microstrip antennas exposes readers to information vital to a wide variety of practical applicationsComputer programs at end of each chapter and the accompanying disk assist in problem solving, design projects and data plotting-- Includes updated material on moment methods, radar cross section, mutual impedances, aperture and horn antennas, and antenna measurements-- Outstanding 3-dimensional illustrations help readers visualize the entire antenna radiation pattern
14,065 citations
Book•
01 Jan 1981
TL;DR: This book discusses techniques and design limitations in two-dimensional arrays of flat-plate antennas, some manufacturing and operational problems of microstrip antennas, and other trends and possible future developments.
Abstract: * Chapter 1: Flat-plate antenna techniques and constraints on performance * Chapter 2: Microstrip design equations and data * Chapter 3: Radiation mechanism of an open-circuit microstrip termination - fundamental design implications * Chapter 4: Basic methods of calculation and design of patch antennas * Chapter 5: Linear array techniques * Chapter 6: Techniques and design limitations in two-dimensional arrays * Chapter 7: Circular polarisation techniques * Chapter 8: Some manufacturing and operational problems of microstrip antennas * Chapter 9: Recent advances in microstrip antenna analysis * Chapter 10: Other trends and possible future developments
598 citations
TL;DR: In this paper, a class of antennas that utilizes arrays of elementary antennas as reflecting surfaces has been investigated, called Reflectarray, which combines much of the simplicity of the reflector-type antenna with the performance versatility of the array type.
Abstract: A class of antennas that utilizes arrays of elementary antennas as reflecting surfaces has been investigated. An antenna of this type is here called a Reflectarray. It has been found that the Reflectarray combines much of the simplicity of the reflector-type antenna with the performance versatility of the array type. The reflecting surfaces employed in these antennas are characterized by a surface impedance that can be synthesized to produce a variety of radiation patterns. The equations of the surface impedance as a function of the desired reflected phase front is derived for the lossless case and methods of realizing this surface impedance are presented. Experimental results of a waveguide array type Reflectarray are given including pencil beam, broad beam and scanning modes. Data on the effects of specific phase errors are presented.
591 citations
TL;DR: In this paper, the effect of thickness is formulated to a second-order approximation, and the result is subjected to numerical differentiation for simple evaluation of the magnetic-loss power factor from the skin depth.
Abstract: The subject is a strip Iine formed of a strip and a parallel ground plane separated by a dielectric sheet (commonly termed "microstrip"). Building on the author's earlier papers all the significant properties are formulated in explicit form for practical applications. This may mean synthesis and/or analysis. Each formula is a close approximation for all shape ratios, obtained by a gradual transition between theoretical forms for the extremes of narrow and wide strips. The effect of thickness is formulated to a second-order approximation. Then the result is subjected to numerical differentiation for simple evaluation of the magnetic-loss power factor from the skin depth. The transition formulas are tested against derived formulas for overlapping narrow and wide ranges of shape. Some of these formulas are restated from the earlier derivations and others are derived herein. The latter include the second-order approximation for a narrow thin strip, and a close approximation for a narrow or wide square cross section in comparison with a circular cross section. Graphs are given for practical purposes, showing the wave resistance and magnetic loss for a wide range of shape and dielectric. For numerical reading, the formulas are suited for programming on a digital pocket calculator.
415 citations
Additional excerpts
...,., /Dielectric Subrtr&-- ieeler [ 8 ] which yields...
[...]
Proceedings Article•
01 Jan 1991TL;DR: In this paper, the microstrip patches with microstrip transmission delay lines are proposed to form a microstrip reflectarray antenna and the results of a theoretical analysis and evaluation of this antenna are presented.
Abstract: In order for a reflectarray to have a thin flat-plate structure, microstrip patches with microstrip transmission delay lines are proposed to form the microstrip reflectarray antenna. The results of a theoretical analysis and evaluation of this antenna are presented. It is shown that, with proper designs, this antenna can have many significant advantages over a conventional parabolic reflector. >
289 citations