Magnetically coupled resonators for achieving low cost narrow band pass filters having high selectivity, low insertion loss and improved out-of-band rejection
US6215374A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 16, 1998 |
| Grant date | Apr 10, 2001 |
| Priority date | — |
| Expiry date | Mar 16, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H7/09
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Parallel and series tuned resonator circuit topologies are disclosed that permit implementation of narrow band-pass filters having high loaded Q and optimal coupling (for low insertion loss) at frequencies in approximately the 50 MHz to 1 GHz. The topologies employ an additional series capacitor for the parallel-tuned topology, and an additional series capacitor for the series-tuned topology, the capacitors having values counterintuitive to those of skill in the art to produce 6.sup.th order transfer functions out of what were once lower order resonators. Multistrip transmission lines are exploited in the parallel-tuned circuit to reduce the inductance of the resonators to achieve a very large skew in the ratios of inductance to capacitance, to increase Q while maintaining optimal coupling between the resonators of the tuned resonator circuits. Air coils are used in the series-tuned topology to achieve the large inductor values desirable for this topology.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.