Millimetre-wave CPS distributed analogue MMIC phase shifter

A millimetre-wave coplanar strip (CPS) analogue distributed MMIC phase shifter is reported for the first time. Since this phase shifter is based on a balanced CPS line, no extra mode transition structure is required for integration with the balanced circuits using CPS or slot lines as well as for packaging in the waveguides. Schottky varactor diodes between the coplanar strip lines are used to control the line capacitance of a synthetic CPS line as a phase shifter, resulting in phase shift. The fabricated phase shifter showed maximum phase shift of 110° and insertion loss of 5.6 dB at 60 GHz.