Dual-mode and quad-mode Mobius bandpass filters

Dual-mode and quad-mode Mobius wire-loaded cavity resonators are being developed for compact bandpass filter applications. Initial results on tuned filters indicate that excellent filter characteristics can be attained in devices that are significantly smaller than traditional wire loaded cavity technology. A novel quad-mode Mobius resonator is presented which occupies the same volume as a dual-mode Mobius resonator. Precisely-controlled dielectric loading of dual-mode Mobius wire loaded bandpass filters has been recently implemented. The passband characteristics are quite encouraging despite the limited tuning used to date.