Micro-electromechanical system (MEMS) digital tunable filter based on micro-mechanical through holes

The invention discloses a micro-electromechanical system (MEMS) digital tunable filter based on micro-mechanical through holes. The MEMS digital tunable filter is fabricated by a MEMS-tolerant body process compatible with a surface sacrifice layer process and comprises a high-resistance silicon substrate, wherein a resonant structure of the filter is arranged above the high-resistance silicon substrate, the micro-mechanical through holes are formed around the resonant structure, the resonant structure is provided with an input end and an output end and comprises a plurality of resonators, the tail end of each level of resonators is connected with a group of MEMS switches, each MEMS switch is provided with a bias network and an air bridge, and the digital tunable variable capacitor is formed after capacitance is applied to the MEMS switches. In the MEMS digital tunable filter, the size of the filter is remarkably reduced by means of the micro-mechanical through holes, different central frequencies and bandwidths are achieved by the MEMS switches, the complexity of a communication system is reduced, the integration degree of the system is improved, and the cost is reduced.