System and method for tuning a narrowband cavity filter used in a CDMA transmitter
US6766150B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 24, 2000 |
| Grant date | Jul 20, 2004 |
| Priority date | — |
| Expiry date | May 24, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J2200/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
There is disclosed a system for tuning a tunable narrowband cavity filter in a base station transmitter of a wireless network. The radio frequency (RF) transmitter comprises: 1) modulation circuitry for modulating an input baseband signal to produce a first RF signal; 2) amplification circuitry for amplifying the first RF signal; 3) a tunable narrowband cavity filter for filtering the amplified first RF signal and transmitting the filtered and amplified first RF signal to an antenna coupled to an output of the tunable narrowband cavity filter; and 4) a system for tuning the tunable narrowband cavity filter. The system for tuning the tunable narrowband cavity filter comprises: a) a filter calibration signal injection circuit for combining an input calibration signal with the input baseband signal; and b) a filter calibration circuit coupled to the output of the tunable narrowband cavity filter for detecting an RF output calibration signal corresponding to the input calibration signal, determining a signal level of the RF output calibration signal, and adjusting a center frequency of a pass band of the tunable narrowband cavity filter in response to the signal level determination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.