On-chip calibration signal generation circuitry is disclosed for filter
tuning for radio-frequency communications and associated methods. On-chip
circuitry generates a calibration signal that is used to help set a
tuning control signal that is received by a tunable front-end filter. In
one embodiment, local oscillator (LO) generation circuitry is used to
generate the calibration signal. In operation of this embodiment, the LO
generation circuitry is tuned to the desired receive channel, or to a
frequency at some offset value from the desired receive channel, and the
output of the LO generation circuitry is then used as a calibration input
signal for a tunable front-end filter. This calibration signal is passed
through the receive path circuitry, and the resulting signal is then
analyzed to help set a tuning control signal for the tunable front-end
filter.