Distributed MEMS Tunable Impedance-Matching Network Based on Suspended Slow-Wave Structure Fabricated in a Standard CMOS Technology

A tunable RF microelectromechanical system (MEMS) impedance-matching network operating at a frequency band from 13 to 24 GHz based on the distributed microelectromechanical transmission line (DMTL) concept is presented in this paper. The network is implemented using a standard 0.35- ¿m CMOS technology and employs a novel suspended slow-wave (SSW) structure on a silicon substrate. The SSW structure results in a reduced total footprint and enhanced impedance coverage. The 8-bit DMTL matching network, fabricated using switched MEMS capacitors and SSW coplanar waveguide on a silicon substrate, results in a wide coverage of the Smith chart up to a maximum voltage standing-wave ratio of 11.5:1 with an impedance matching better than 10 dB and a power transfer ratio of better than -2.84 dB at 24 GHz. To our knowledge, this is the first implementation of a DMTL tunable MEMS impedance-matching network using a standard CMOS technology.