Compact Vertically Polarized 2-bit Fixed-Frequency Beam-Scanning Array with Integrated Phase Shifters

A reconfigurable bit array is a simplified and cost-effective method for fixed-frequency beam scanning compared to phased array. This work introduces a 2-bit fixed-frequency beam-scanning array with vertical polarization based on transmission lines with integrated shifters. In this letter, the lower main microstrip line crosses the center line of the upper radiating array. The radiating unit, an offset-fed patch, is connected to a pair of floating microstrip lines and feed vias, and four p-i-n diodes are loaded to provide the required 2-bit phase states. A ten-unit vertically polarized 2-bit scanning array is designed at 5 GHz. The transverse width of 0.9λ₀ is smaller than that of most linear scanning arrays, which is advantageous in space-constrained applications. The measured results show that the E-plane beam can be continuously scanned from −64° to +64°, realized gains vary between 8.3 dBi and 12.2 dBi, cross polarization levels are better than 11.1 dB, and sidelobe levels fluctuate around 6.8 dB.