Power-dependent Microstrip Bandstop Filter Enabling RF Interferer Tracking and Automatic Stopband Attenuation Adjustment

This paper presents a novel class of power-dependent bandstop filters (PDBSF) that can be used to effectively suppress dynamic RF interference in scenarios involving 1-variable frequency, 2-variable power, and 3-variable frequency and power. The proposed circuit consists of a signal tracking bandstop filter, an input coupler for measuring the input power, and an electronic feedback circuitry. The PDBSF is implemented using microstrip transmission line technology and simulated using Momentum ADS. The tuning range of the proposed BSF filter is approximately 245 MHz to 295 MHz, while the power range that can be covered is up to 5 dBm. Simulation results demonstrate that the PDBSF can effectively suppress any in-band interference with variable frequency and power.