Piezoelectric MEMS Actuator-Based Tunable SIW Filter for 5G Communication

A Novel Piezoelectric MEMS Actuator is designed to tune the Evanescent SIW filter for Ka-band applications. A piezoelectric actuator is attached to the EVA-mode SIW filter resonator. The Evanescent SIW resonator is designed over RT Duroid 5880, having a dielectric constant εr = 2.22, whose substrate thickness is 0.787 mm with conductor thickness of 17 m. Capacitive post and DGS are loaded on the SIW cavity resonator to reduce the footprint of the structure. DGS adds a transmission zero to improve the out-of-band rejection of the SIW filter. The Piezoelectric Actuator is attached to the SIW filter and placed above the capacitive post. An actuation voltage of 17 V is applied to the top metal layer of the to deflect the actuator in upward direction by 50 m. The capacitance underneath the actuator varies, which subsequently varies the resonance. Tunability range of 960 MHz between 27.69 and 28.65 GHz is achieved.