Tracking filter for a television tuner

An apparatus comprising:

• a tracking filter to be coupled between a front end amplifier that is to receive a television signal and a mixer that is to downconvert the television signal to an intermediate frequency (IF) signal, wherein the tracking filter includes a plurality of tanks each to cover a band of television channels, at least one of the tanks having an inductor configured as a magnetically differential inductor having at least one positive turn and at least one negative turn that are cross-coupled, wherein the at least one positive turn travels from a first metal layer of a first semiconductor die to a second metal layer of the first semiconductor die, and the at least one negative turn travels from the second metal layer to the first metal layer, the magnetically differential inductor to reduce magnetic interference and provide common mode rejection, and the plurality of tanks each further having a capacitor array coupled between a first line and a second line, each capacitor array including a set of parallel paths having at least one capacitor and a switching device to controllably couple the corresponding at least one capacitor to the first and second lines, wherein a Q profile of the capacitor array is to increase over an increasing frequency range of the corresponding band;
• a capacitor attenuator coupled between the plurality of tanks and the mixer;
• and
• a table to store a corresponding compensation factor for each tracking filter at each of a plurality of settings of the capacitor attenuator, wherein the compensation factor is to maintain tuning of the tracking filter at the corresponding capacitor attenuator setting.

A method comprising:

• setting a tuning value for a capacitor array of a tracking filter of a television tuner coupled between an amplifier and a mixer to an initial value for a corresponding setting of a capacitive attenuator coupled between the tracking filter and the mixer, setting a threshold of a peak detector coupled to the capacitor array to cause an output of the tracking filter to trip the peak detector, and decrementing the peak detector threshold;
• sequentially incrementing the tuning value and determining whether the peak detector trips, until the peak detector does not trip;
• storing the tuning value when the peak detector does not trip in a first storage;
• sequentially decrementing the tuning value and determining whether the peak detector trips, until the peak detector does not trip;
• storing the tuning value when the peak detector does not trip in a second storage;
• and
• calculating a tuning code for the capacitor array to be substantially an average of the values stored in the first and second storages, and storing the tuning code in a compensation table.