C-band 6-bit phase shifter for a phase array antenna

A C-band 6-bit digital phase shifter is presented.The phase shifter is based on the synthetic design of a high-pass/low-pass network and the all-pass network.The series scatter restrain method is also discussed.The phase shifter is fabricated in 0.25μm GaAs PHEMT technology and developed for C-band phased arrays,and the relative phase shift varies from 0 to 360 in step of 5.625°.The phase shifter,with a chip size of 4×1.95 mm~2,has achieved an insertion loss better than 6.4 dB,RMS phase error of less than 1.73°,and an input and output VSWR less than 1.6 at all conditions.