Trimming of local oscillation in an integrated circuit radio

摘要

A method and apparatus for trimming of a local oscillation within a radio frequency integrated circuit (RFIC) includes processing that begins when an RFIC receives a radio frequency (RF) signal having a known frequency. The processing then continues when the RFIC mixes the RF signal with a receiver local oscillation to produce a low intermediate frequency (IF) signal, which may have a carrier frequency of zero (i.e., a baseband signal) or up to a few mega Hertz). The processing then continues when the RFIC demodulates the low IF signal to produce demodulated data. The processing then continues as the RFIC determines a DC offset from the demodulated data, where the DC offset is reflective of the difference between the known frequency and the frequency of the receiver local oscillation. The processing then continues as the RFIC adjusts the receiver local oscillation to reduce the DC offset when the DC offset compares unfavorably with an allowable offset threshold.