Wide tuning range MEMS band-pass filter with inductance change

This paper describes a tunable band-pass filter (BPF) operating in the frequency range of 8-12 GHz. The filter consists of three resonators and four series coupling metal-insulator-metal (MIM) capacitors. The tuning approach is to change the inductance values of each resonator while all the capacitance values are kept as constant. The inductance change is achieved by changing the length of the shorted-stub using metal-metal contact switch. Results show that the center frequency of the tunable BPF can be shifted from 8 GHz to 12.3 GHz with 50 % tuning range. The 3 dB bandwidth can be kept around 10 % in the whole tuning range. The insertion loss is varied between 9 dB and 11 dB.