Reflectarray antennas composed of rectangular grooves with sub-wavelength holes on a metal plate are designed for millimeter-wave regions. All depths of multiple grooves in the metal reflectarray are elaborately manipulated for a high-gain reflector. A sub-wavelength hole in each groove reduces the mass of the reflectarray antenna, which rarely affects the re-radiated millimeter-wave filed from the groove. In this paper, we have demonstrated light high-gain reflectarray antennas and achieved a 25%-light reflectarray antenna compared with a metal reflectarray without sub-wavelength holes. The designed reflectarray antenna operates within the 15% wide-band bandwidth at 3 dB for millimeter-wave band.
To fulfill the dual-frequency requirements, elements are needed to resonate at two different, independently adjustably frequencies. A low weight, low cost, and easy to fabricate single-layer dual-frequency reflectarray is designed, fabricated, and measured, with gain values of 27 and 29.2 dBi at 20 and 30 GHz, respectively.
Abstract
A single-layer wideband high efficiency reflectarray in Ku-band has been presented in this paper. A novel dual-resonant patch element approach has been analyzed and optimized to obtain good radiation performances within the operating frequency band. The phase shift range of 573° can be obtained with less steep linear phase shift curve. To compensate the differential spatial phase delays from the feed to the elements, the variable size technique has been utilized for obtaining required phase shifts. The reflectarray aperture has been designed, manufactured and measured. Measured results are in good agreement with the simulated ones. The measured gain of the reflectarray aperture at center frequency can reach 27.2 dBi, which is equivalent to aperture efficiency of 51.3%, and the 1-dB gain bandwidth of the aperture is 18.4%.
Millimeter-Wave Metal Reflectarray Antennas with Sub-Wavelength Holes