A Ka-band microstrip reflectarray with elements having variable rotation angles

作者：J.C. Huang, Ronald J. Pogorzelski · 发表于：IEEE Transactions on Antennas and Propagation · 年份：1998 · DOI：10.1109/8.668907 · 被引用次数：594 · 研究领域：Advanced Antenna and Metasurface Technologies、Antenna Design and Analysis、Metamaterials and Metasurfaces Applications

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.