A reconfigurable RF MEMS low-pass filter, based on CPW periodic structures

This paper addresses the design and the realization of millimeter wave tunable filters using multiple-contact MEMS switches. The two unit cell filter based on slow-wave coplanar waveguide(CPW) periodic structure are reconfigured into a self-similar single unit cell by the operation of MEMS switches with single actuation. The 3-dB cutoff frequency of the low-pass filter was shifted from 12.5 GHz to 6.1 GHz, which exhibits excellent performance on small size, low insertion loss and is compatible with monolithic microwave integrated circuit technologies. The tested results show that the pass-band ripple is less than 0.5 dB and the out-of-band rejection is better than 40 dB. The driven voltages of the switches are around 25 V.