Band rejection filter having integrated impedance inverter-tune cavity configuration
US4100504A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 20, 1977 |
| Grant date | Jul 11, 1978 |
| Priority date | — |
| Expiry date | Jun 20, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D9/0625
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
For eliminating an unwanted leaking local oscillator signal from the output of a double-balanced mixer circuit in a microwave frequency up-converter, a band rejection filter formed of series connected impedance inverter elements and a plurality of tuned cavity resonators is provided. The cavity resonators are integrally formed by the cylindrical walls of an aluminum housing, the top portion of which is formed of a plated printed circuit board. That face of the printed circuit board which faces the cylindrical cavities of the resonators is plated with copper to form the upper surface of each resonator. The other side of the printed circuit board is selectively plated with copper layers which extend through the board to the lower layer to provide an extensive ground plane. The impedance inverter elements themselves are formed of quarter-wavelength coaxial cable sections and are directly connected between the tuning stubs of the cavity resonators and have their outer conductor jackets directly soldered to the ground plane. The compactness of the band rejection filter permits it to be disposed in a housing arrangement between the printed circuit cards upon which the active components o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.