IMPROVED MULTI-CAVITY DIELECTRIC FILTER

摘要

A multi-cavity dielectric filter 30 having a single housing 32 for a plurali ty of resonant cavities 65. The dielectric filter 30 has a plurality of dielectric resonators 42 placed inside housing 32, instead of in individual housings, wherein the resonators 42 are spaced a quarter wave apart and are electrically isolated from one another b y conductive isolation plates 44 positioned therebetween. The isolation plates 44 do not make continuous mechanical contact with the interior conducting surface of housin g 32, but rather are spaced from the inner surface 77 of housing 32, thereby making assembly of the filter much simpler than if a solid RF connection had to be made. The resonators 42 are positioned inside the housing 32 between the isolation plates 44 and are supported by low loss, low dielectric constant spacers 46. End walls 59 complete the cavi ty formation at the termination ends 79 of housing 32. For a band reject filter, the cavities are joined by coupling loops connected to a transmission line while for a bandpass filter, apertures are placed in the isolation plates (44') so as to couple electromagnetic energy between adjacent cavities (65).