S band Six-bit Digital Phase Shifter for RADAR applications

This paper presents design and test results of compact monolithic 6-bit digital phase shifter (DPS) at S-band for radar applications. The optimum design topology of each bit is selected based on insertion loss, amplitude and phase errors and compactness. The phase shifter is fabricated using $0.25 \mu \mathrm{m}$ p-HEMT GaAs process from UMS foundry. The developed DPS is realized within the footprint of $4.8 \mathrm{~mm} \times 2.6 \mathrm{~mm} \times 0.1 \mathrm{~mm}$, exhibits $6.0 \mathrm{~dB}$ insertion loss with salient features of voltage wave standing ratio of less than 1.57, RMS amplitude error less than $0.30 \mathrm{~dB}$ and RMS phase error better than 1° at 3.2GHz with 100 MHz bandwidth.