Patent ID: 6766150
Filing Date: 2004-07-20
Classification: H03J

Abstract:
A radio frequency (RF) transmitter comprising:modulation circuitry capable of modulating an input baseband signal to produce a first RF signal; amplification circuitry capable of amplifying said first RF signal; a tunable narrowband cavity filter capable of filtering said amplified first RF signal and transmitting said filtered and amplified first RF signal to an antenna coupled to an output of said tunable narrowband cavity filter; and a system for tuning said tunable narrowband cavity filter comprising: a filter calibration signal injection circuit capable of combining an input calibration signal with said input baseband signal; and a filter calibration circuit coupled to said output of said tunable narrowband cavity filter capable of detecting an RF output calibration signal corresponding to said input calibration signal, determining a signal level of said RF output calibration signal, and adjusting a center frequency of a pass band of said tunable narrowband cavity filter in response to said signal level determination.