Design of 2.5-3.3 GHz high-precision compact digital phase shifter

Abstract

A 6-bit MMIC digital phase shifter, designed using a 0.5 μm GaAs pHEMT process, has been developed to enhance the search capability of phased array systems for targets. The chip structure of the phase shifter is well-designed, and the improved embedded topology of the 45° and 90° phase shifting units effectively reduces the overall insertion loss. To reduce the chip size, the phase shifting units with smaller layouts of 5.625°, 11.25°, and 22.5° are combined, greatly reducing the chip area. The results show that within the frequency range of 2.5-3.3 GHz, the input and output VSWR is less than 1.38, the insertion loss is less than 4.3 dB, the root mean square phase error of the phase shifting state is less than 1.43°, and the absolute value of the amplitude fluctuation for different states is less than 0.52 dB. The compact chip structure measures 2.45 mm×1.08 mm.