A cavity filter using stepped impedance coupling resonator

This paper presents a cavity filter based on an alternative control method using stepped impedance coupling resonators, while conventional cavity filters use coupling screws, to adjust coupling value between adjacent resonators. Using 3-D EM simulation, it is proved that coupling screws can be successfully replaced using the proposed stepped impedance coupling resonator between adjacent cavity resonators. For the proposed stepped impedance resonator, a coupling coefficient is found from a simulation in order to design a band pass filter. A proper iris area and a resonator angle are obtained using a 3-D EM simulation. The band pass filter based on the proposed stepped impedance resonator was successfully synthesized to have good pass-band and stop-band performances from the 3-D EM full-wave simulation, which verifies the proposed scheme.