POLARIZED BAND PASS FILTER

摘要

PURPOSE:To improve the pressure and voltage resistance characteristics at a coupled part, by coupling two resonators with a rectangular slot having a large width. CONSTITUTION:In the case of the primary coupling (with susceptance BL3) between resonators 21 and 22 consisting of circular waveguides by means of an inter-stage coupling slot 9, a magnetic dipole M1 is used for coupling with mode H between resonance circuits Q2 and Q3. While a magnetic dipole M2 is used with mode V between resonance circuits Q1 and Q4 in the case of the indirect coupling (with susceptance BL4) by means of the slot 9. The coupling coefficient (K23) of the primary coupling with the slot 9 is shown as K23= M1lambda0<2>/lC<3>(3R0<2>); while the coupling coefficient (K14) of the indirect coupling with the slot 9 is expressed as K14=DELTAomega<2>/2alpha=M2lambda0<2>/lC<3>(3R0<2>) respectively. The inserting direction of a capacitive screw is shifted by 90 deg. to other capacitive screws to obtain the phases of electric field opposite to each other between the circuits Q1 and Q4. At the same time, a relation M1>>M2 is satisfied. As a result, an attenuation pole can be produced at an attenuation region.