Broadband Monolithic 6-Bit Digital Phase Shifter

This paper presents the design, fabrication and characterization of a multi-octave 6-bit digital phase shifter MMIC with on-chip drivers using GaAs pHEMT technology. Amplitude compensation technique is used to control the insertion loss variation over the states. This wideband phase shifter maintains a low phase error of 5deg mid-band, low insertion loss of 14dB, good input-output VSWR and less amplitude variation with phase states, over the entire frequency range. The complete circuitry including the digital interface occupies a chip area of 5mm×3.5mm.