Micromachined Millimeter-wave Ridge Waveguide Filter with Embedded MEMS Tuning Elements

This paper demonstrates the feasibility of constructing micromachined 3-dimensional ridge waveguide filters with built-in tuning elements. The objective of the tuning elements is to fine tune the filter in order to compensate for the fabrication tolerance of the micromachining process. A novel micromachined ridge waveguide filter with a coplanar line input/output interface is proposed. The structure is analyzed both theoretically and experimentally. A 2-pole micromachined millimeter-wave filter with embedded MEMS actuators as tuning elements is designed, fabricated and tested to demonstrate the concept. At 24 GHz, the filter size is only 2mm times 4mm