Nonlinear Matched Reflection Mode Bandstop Filters for Frequency Selective Limiting Applications

This paper presents the design of frequency-selective limiting circuits based on nonlinear matched reflection-mode bandstop resonators. This type of frequency selective limiters achieve fast switching, high-level of power limiting, and flexible channel bandwidth. Initial measured results of a first-order device indicate 0 dBm limiting threshold, 32 dB limiting level, 2 dB insertion loss, and 200 MHz limiting bandwidth. A third degree device is also presented. Simulated results show an excellent highly selective bandstop performance at high powers with a near all-pass response at low signal powers. This is the first time such a multi-pole matched frequency selective limiter has been reported.