Design of Polarization-Reconfigurable Beam-Scanning Monopulse Phased Array

In this communication, a multifunctional phased array with polarization reconfiguration, beam scanning, and monopulse functions is presented for advanced satellite applications based on a 2 bit phase-shifting network and planar monopulse comparator. The diodes embedded in the upper patch independently control the polarization modes of the proposed phased array, including linear polarization (LP), left-handed circular polarization (LHCP), and right-handed circular polarization (RHCP). The planar monopulse comparator located in the middle layer can flexibly switch the sum and difference patterns in both azimuth and elevation planes. The bottom phase-shifting network consists of
$8\times2$
2 bit phase shifters, which makes the proposed phased array have beam-scanning characteristics in the azimuth plane. Therefore, both the sum and difference beams can be scanned from −50° to +50° in xo z plane at all polarizations. A prototype is fabricated for demonstration. When the scanning angle is changed from 0° to −50° in
$xo\text {z}$
plane, the measured peak gain of sum beam ranges from 11.8 to 9.1 dBi (12 to 9.5 dBic) at LP (LHCP) radiation mode. And the measured maximum null-depths of difference beam are all below −19.8 dB (−17.6 dB) with high amplitude balance in LP (LHCP) radiation mode at boresight in
$yo\text {z}$
plane. Simulated and measured results are in good agreement.