Band 3+ RF MEMS micro switch and its application to a high power tunable filter

In military communication applications, tactical scenarios demand octave range tunability and high power handling. As a main component of a highly tunable filter, low-loss switches are desired to dynamically select components which tune the filters. This paper presents the design, the simulation, the manufacturing and the testing of tunable filter with in-line and integrated RF micro switches that operates in Band 3+ (1.35 to 2.7 GHz). The four states tunable filter is a microstrip half-wavelength resonator. The filter is wideband (1.597 to 2.295 GHz) and very selective with relative bandwidth from 1.6% to 4%. This operation band requires in general large-scale filter size and loss. The proposed design takes less than 1 cm² and has acceptable insertion loss. Several micro switches are used with resonators to commute large scale surface to form a four-state tunable filter. The switches and resonators are designed such that the complete tunable filter is fabricated during the same manufacturing process.