A X-band 4-bit mHEMT phase shifter

A 4-bit X-band phase shifter is developed using 0.15/spl mu/m mHEMT technology. The mHEMT technology has an (Ron . Coff) = 0.25 pS, minimizing the switch insertion loss. Three different bit topologies are used to achieve both first pass success and best possible performance. The phase shifter operates between 8-12 GHz with 5.5 dB mean insertion loss, +/- 0.7 dB amplitude error, less than 5/spl deg/ RMS phase error, and better than 10 dB return losses. The die area is 1.7 mm/sup 2/.