A W-band InGaAs PIN-MMIC digital phase-shifter using a switched transmission-line structure

This paper describes the design and fabrication of a W-band InGaAs PIN-diode MMIC 4-bit phase shifter based on a switched delay line. In order to achieve low insertion loss and good phase shifting characteristics at W-band, the topology based on a switched delay-line is employed using a thin-film microstrip line structure. The fabricated phase shifter has demonstrated good performances such as an insertion loss less than 12.7 dB at a frequency range of 81 to 85 GHz with an intrinsic chip size of 1.93 × 0.80 mm². To our knowledge, this is the first InGaAs PIN MMIC digital phase shifter demonstrated up to W-band.