Grating lobe reduction of sparse array with pattern reconfigurable element by time-domain synthesis

Abstract

Small element spacing is typically employed in phased array antennas to avoid grating lobes. However, the small element spacing limits the element gain. We have proposed a grating lobe reduction technique for a sparse array antenna with radiation pattern reconfigurable elements. It can reduce the grating lobe and improve the gain of the scanning angle. In this paper, we propose an additional grating lobe reduction technique that utilizes reconfigurable radiation patterns and time-domain synthesis. Two radiation patterns are generated in the time-domain; the element pattern is changed whereas the phase of each element remains unchanged. An equivalent low grating lobe pattern can be obtained by synthesizing two patterns based on a simple equation. We apply this method to the measured result of our radiation pattern reconfigurable antenna and its simulation; this results in significant GL reduction.