A Switchable Iris Bandpass Filter Using RF MEMS Switchable Planar Resonators

A concept of using planar circuit resonance to disable 3D cavity resonance inside a rectangular waveguide filter is demonstrated. Switchable RF MEMS planar resonators are introduced inside the resonant cavities of a high Q-factor iris bandpass filter to turn the filter ON and OFF. The measurement confirms that this high Q-factor filter with insertion loss better than 0.1 dB can be converted to a bandstop filter with an isolation better than 30 dB for the same frequency and bandwidth.