Tunable RF filters based on radially loaded evanescent-mode cavity resonators

The rapid development in wireless communication technologies has resulted in evermore complex RF and microwave communication systems. A promising solution to these challenges is reconfigurable wireless communication systems whose hardware parameters, such as frequency, bandwidth, power and efficiency, can be changed to make better use of the available spectrum. Tunable filters represent integral and critical components in such systems. In particular, tunable RF bandpass filters can be used for band selection, image rejection, and elimination of out-of-band emissions. Tunable bandstop filters enable dynamic rejection of interferers, thus improving the sensitivity and dynamic range of receiver systems.