Frequency agile bandstop filter (FABSF)

Abstract

The frequency agile bandstop filter (FABSF) is an RF system component that functions as a frequency agile tunable notch filter capable of rejecting the low-level noise in presence of a high-level signal such as the out-of-band noise at the output of a high-power amplifier. The FABSF finds application in a frequency agile duplexer (FAD) system architecture to be implemented in the RF front-end of frequency division duplex (FDD) radio.