ReconfigurableFilters on Low Loss Substrates forFlexibleFront Ends

Different examples oflowloss, widely reconfigurable filters areshown.Thefirst example concerns a2pole, tuneall filter, builtusingfive3 bitswitched varactors. Thesecond exampleisabouta 2 pole2 bitswitched filter built using appropriate distribution ofswitched capacitor alonganhairpin resonator. RF-MEMS,Tunable filters andreconfigurable front ends J.INTRODUCTION RF-MEMStechnology allows toachieve verylowloss, highly linear, wideband matching networks andfilters. Indeed, fromthemicrowave engineer viewpoint, RF-MEMSallow to build highimpedance tunable elements, through theuseofair gapmetal airmetal capacitances. Also, electrostatic actuation permits toachieve nearzeropowertuning, andverylowloss biasing networks. However, designing efficient circuits with this technology, requires verycareful design, andspecial care forimplementation ofMEMS switches andvaractors. Itisinteresting tonotethat bothcapacitive switches and ohmicswitches canbeusedtoachieve thishighlevel of performances, since thecontrast between onandoffstate compensates fortheonstate resistance ofohmicswitces compare withcapacitive switches. We willpresent inthis papertwo examples ofohmicRF-MEMS switchand capacitive MEMS tuned filters (1-6)