Analysis and Design of Wide-Scan Phased Array Using Polarization-Conversion Isolators

In this letter, a linear wide-scan phased array using a polarization-conversion isolator (PCI) is analyzed and designed. The directivity of a linear array composed of isotropic sources against the scanning angle is investigated to reveal that the mutual coupling (MC) between adjacent elements is the major constraint on the scanning range when the interelement spacing is less than half free-space wavelength. A PCI is adopted to broaden the scanning range, and the MC reduction principle is studied. A 16-element linear phased array with the PCIs is designed. A prototype is fabricated and measured, and the measured results show that the designed array can scan its main beam from -72° to +72° with a gain fluctuation less than 2.5 dB. Besides, the variation of the array realized gain with the scan angle validates that the linear array layout benefits for the scanning range.