Millimetre Wave Phase Shifters Based on a Metal Waveguide with a MEMS-Based High-Impedance Surface

An electronically reconfigurable high-impedance surface (HIS) based on microelectromechanical systems (MEMS) is manufactured and proposed for novel millimetre and submillimetre wave phase shifters. Typically HIS is a capacitive metal grid placed on a dielectric substrate with a ground plane with impedance varying from an initial value to a very high value depending on the frequency of the incident field. Such phase shifters can be developed by introducing a surface with variable impedance in, e.g., a rectangular metal waveguide. In this paper we present design, characterization and measurements of the MEMS-based HIS and of a reflection type phase shifter at 80 GHz