Vibration mitigation for evanescent-mode cavity filters

This paper presents the first vibration mitigation technique for evanescent-mode cavity filters. The effect of vibration is substantially reduced by over 20 dB by injecting a voltage signal on the bias of the tuning piezoelectric device. The vibration is measured by an accelerometer and the frequency and amplitude of this signal is chosen based on the analysis of the measured acceleration. The proposed technique has the potential to be fully implemented in an electronic monitoring system. The vibration mitigation approach is tested on a 2-pole Bandstop Filter (BSF) tuned to 1.3 GHz. The sidebands caused by vibration are reduced by 24-26 dB.