X band 6-bit Digital Phase Shifter GaAs MMIC Design for T/R Modules

Design and measured results of X band 6-bit digital phase shifter MMIC is presented in this paper. This phase shifter is designed in the frequency range of 8.5-10.5GHz with phase resolution of 5.6° The design is based on a GaAs Enhancement/Depletion Process. Topology architectures for the design of the individual phase bits are derived to maintain low insertion loss, flat phase response and small MMIC die size. TTL driver circuit is embedded in the design to control the phase shift with TTL control inputs. It works on +5V,-5V Supply voltages. The measured results of digital phase shifter are 6dB insertion loss, 3° RMS phase Error, Peak phase Error of ±10° and RMS amplitude error of 0.4dB across the all 64 phase states.