High-Q RF filter with printed circuit board mounting temperature compensated and impedance matched helical resonators
US4682131A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 7, 1985 |
| Grant date | Jul 21, 1987 |
| Priority date | — |
| Expiry date | Jun 7, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K1/16
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A helical filter is disclosed which includes a ground plane having microstrip transmission line segments to which a respective helical resonator coil is connected at the high impedance end thereof. A discrete capacitor is connected in parallel with each transmission line. A housing is provided with individual resonator compartments which effect associated distributed capacitance with the resonators themselves, which capacitance may be adjusted by included tuning screws. Conductors are connected to and form an integral part of a given two of said transmission lines and serve as the input and output for the helical filter. The transmission line and discrete capacitor pair provides the necessary impedance match, while the capacitor itself facilitates temperature compensation and frequency range selection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.