A Band-Stop Filter with Far Spurious Stop Bands

Abstract

This paper presents a band-stop filters with far spurious stop bands. At first, a coaxial cavity with far spurious stop band is proposed. Then several such coaxial cavities are connected in series to form a band-stop filter. To illustrate the design process, a coaxial band-stop filter has been designed, with a stop-band centered at 5 GHz, a bandwidth of 2 GHz, and its first spurious stop-band higher than 18 GHz. The sample filter has been fabricated and tested. Tested results show good agreement with simulated results. The parameters of the band-stop filter are explicitly derived from those of a standard filter, which is assumed as a reference. It has been proved in both the simulation and the measurement.