MEMS-based reflective-type phase-shifter for emerging millimeter-wave communication systems

In this paper a 3-bit reflective-type phase shifter with shunt switches using MEMS technology is implemented. The phase shifter employs a 90 hybrid broadside coupler with two reflective loads. Those loads have variable short ended lengths of transmission lines. The short end in those loads are implemented by the metal to metal contact shunt switches over a segment of CPW line. The average insertion loss of the phase shifter is 3.9 dB over all states at 60 GHz. The dimensions of the phase shifter is 11 mm × 2 mm. This phase shifter can be integrated with planar antennas at 60 GHz for high performance phased array systems.