TUNER INPUT FILTER WITH ELECTRONICALLY ADJUSTABLE CENTER FREQUENCY FOR ADAPTING TO ANTENNA CHARACTERISTIC

摘要

A system, apparatus and/or method provides frequency response adjustment of an RF input filter (208) of an RF tuner (40) based on impedance of an antenna system (24) that is providing reception of RF signals to the RF tuner. The frequency response adjustment is preferably accomplished dynamically and/or with respect to each frequency tuned. Particularly, the system, method and/or apparatus provides compensation at the RF tuner level for mistuning effects produced on the RF tuner (40) by antenna system impedance (29) presented at the antenna input (30) that is other than a designed for impedance. Frequency response of an RF input filter (208, 216) for the RF tuner (40) is electronically adjustable with an independent or semi-independent control voltage signal based on one or more measured parameters of a tuning frequency. Frequency response adjustment may include adjustment of a center frequency of the RF input filter bandpass frequency range and/or altering the bandpass frequency range of the RF input filter. The subject invention expands the capability of an RF signal receiver, particularly one using at least one electronically adjustable RF filter at the input of an electronic alignment type tuner.