An adjustable impedance matching network using RF MEMS technology

Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Electrical and Electronics Engineering, Turkey

Approval Date: 2003




This thesis presents design, modeling, and fabrication of an RF MEMS adjustable impedance matching network. The device employs the basic triple stub matching technique for impedance matching. It has three adjustable length stubs which are implemented using capacitively loaded coplanar waveguides. The capacitive loading of the stubs are realized using the MEMS switches which are evenly distributed over the stubs. There are 40 MEMS bridges on each stub whichare separated with ?/40 spacing making a total of 120 MEMS switches in the structure. The variability of the stub length is accomplished by closing the MEMS switch nearest to the required stub length, and making a virtual short circuit to ground. The device is theoretically capable of doing matching to every point on the Smith chart. The device is built on coplanar waveguide transmission lines. It has a center operating frequency of 10GHz, but because of its adjustability property it is expected to work in 1-40GHz range. It has dimensions of 8950 ₉ 5720æm2. This work is the continuation of the first national work on fabrication of RF MEMS devices. The device in this work is fabricated using the surface micromachining technology in the microelectronic facilities of Middle East Technical University.