Low-loss tunable radio frequency filter

摘要

An RF filter comprises a signal transmission path having an input and an output, a plurality of resonant elements disposed along the signal transmission path between the input and the output, and a plurality of non-resonant elements coupling the resonant elements together to form a stop band having a plurality of transmission zeroes corresponding to respective frequencies of the resonant elements, and at least one sub-band between the transmission zeroes. The non-resonant elements comprise at least one variable non-resonant element for selectively introducing at least one reflection zero within the stop band to create a pass band in a selected one of the sub-band(s). The RF filter further comprises an electrical controller configured for receiving an operating temperature, and adjusting the variable non-resonant element(s) based on the received operating temperature, thereby selectively moving the reflection zero(es) along the stop band to move the pass band within the selected sub-band.

主权项

1. A radio frequency (RF) filter, comprising:
a signal transmission path having an input and an output; a plurality of resonant elements disposed along the signal transmission path between the input and the output; a plurality of non-resonant elements coupling the resonant elements together to form a stop band having a plurality of transmission zeroes corresponding to respective frequencies of the resonant elements, and at least one sub-band between the transmission zeroes, wherein the non-resonant elements comprise at least one variable non-resonant element for selectively introducing at least one reflection zero within the stop band to create a pass band in a selected one of the at least one sub-bands; and an electrical controller configured for receiving an operating temperature, and adjusting the at least one variable non-resonant element based on the received operating temperature, thereby selectively moving the at least one reflection zero along the stop band to move the pass band within the selected sub-band.