PURPOSE: To obtain a dielectric filter with small size, low loss and capable of adjustment of coupling by forming a shape of an open end face of a dielectric coaxial resonator to be rectangular and arranging a dielectric resonator side by side at the long side.
CONSTITUTION: No conductor film is formed to a surface of throughholes 11-14 with opening formed with inner conductors of dielectric coaxial resonators 1-4 but the surface is an open end face and the shape of the open end face is rectangular and the size in a direction of the resonators 1-4 opposite to each other is longer than the size in a direction of arranging the resonators 1-4. Cavities 21-23 are formed among the resonators 1-4 while the recessed part formed to each resonator is opposite to each other, no conductor film is formed to the cavities 21-23 and the capacitive coupling and the inductive coupling among the adjacent resonators are obtained through the cavities 21-23. The coupling state among the resonators is decided by the position and the size of the cavities 21-23. Thus, the size is decreased and the loss as the filter is reduced and the adjustment of the coupling among the resonators is facilitated.
MIYASHITA AKIJI
MIYOSHI SATOSHI
SANO KAZUHISA
| JPS63314001A | 1988-12-22 | |||
| JP58123606B | ||||
| JP64015401B | ||||
| JP61140604B | ||||
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| JPS58161401A | 1983-09-26 |