Patent ID: 8973059
Filing Date: 2015-03-03
Classification: H04H,H04N

Abstract:
1. An apparatus comprising: a filter coupled to a source of a first signal and a second signal, said filter including a high-pass filter; a tunable trap filter coupled to said filter for filtering said second signal within a passband of said filter; and a demodulator for demodulating said first signal and determining a signal parameter of at least one of said first signal and said second signal and generating a control signal for controlling said tunable trap filter in response to said signal parameter, wherein said tunable trap filter includes a capacitor coupled to an output of said high-pass filter, an inductor coupled to said capacitor, a resistor coupled to said inductor and to said demodulator, a varactor diode coupled to said inductor, to said resistor, and to a ground potential; said control signal adjusts a bias voltage applied to said tunable trap filter responsive to said signal parameter, said bias voltage is used to adjust the resonant frequency of said tunable trap filter, and said tunable trap exhibiting a high Q characteristic rejects said second signal, said second signal including ATSC or other unwanted terrestrial signals that may be present on said filter under a single-wire multi-switch (SWM) environment.