Title :
Low Side-Lobe Circularly-Polarized Phased Arrays Using a Random Sequential Rotation Technique
Author :
Smolders, A.B. ; Visser, H.J.
Author_Institution :
Eindhoven Univ. of Technol., Eindhoven, Netherlands
Abstract :
A novel technique is presented for sidelobe and axial ratio control of circularly-polarized phased array antennas. Although our new random sequential rotation (RSR) concept uses a regular periodic array grid, it provides similar properties as randomly-spaced array antennas. In this way, a wideband behavior is provided, without the appearance of grating lobes. In addition, the gain is maximized, since a uniform amplitude distribution is used. A 4 GHz prototype consisting of 16 aperture-coupled microstrip antennas with a beamformer was developed to demonstrate the basic properties of RSR array antennas. Although the element spacing is much larger than half a wavelength, well-controlled sidelobes are provided, even in the worst-case diagonal plane. The measured cross-polarization level at 4 GHz is below -20 dB at a 20-degree scan angle in the diagonal-plane.
Keywords :
antenna phased arrays; antenna radiation patterns; broadband antennas; microstrip antenna arrays; microwave antenna arrays; polarisation; RSR array antennas; RSR concept; aperture-coupled microstrip antennas; axial ratio control; beamformer; circularly-polarized phased array antennas; element spacing; frequency 4 GHz; random sequential rotation concept; randomly-spaced array antennas; regular periodic array grid; sidelobe control; wideband behavior; Gratings; Microstrip antenna arrays; Phased arrays; Polarization; Prototypes; Quantization (signal); Circular polarization; phased array antennas; random array; sequential rotation; wideband array;
Journal_Title :
Antennas and Propagation, IEEE Transactions on
DOI :
10.1109/TAP.2014.2359476