Abstract: An apparatus and method for filtering a signal is described. The apparatus includes a first singly terminated filter that filters a signal in a first frequency range, and a second singly terminated filter that filters the signal in a second frequency range, the inputs of the filters being connected together, wherein an element of the first filter is coupled to an additional element to form a frequency response transmission zero in a stopband frequency range of the first filter. The method includes receiving a signal, the signal containing content from a first source in a first frequency range and content from a second source in a second frequency range different than the first range, applying filtering, and applying filtering to generate a second output signal, using filters that include a singly terminated filter section with additional circuit elements to form a transmission frequency zero in the stopband frequency range.

Abstract: An apparatus and method for filtering a signal is described. The apparatus includes a first singly terminated filter that filters a signal in a first frequency range, and a second singly terminated filter that filters the signal in a second frequency range, the inputs of the filters being connected together, wherein an element of the first filter is coupled to an additional element to form a frequency response transmission zero in a stopband frequency range of the first filter. The method includes receiving a signal, the signal containing content from a first source in a first frequency range and content from a second source in a second frequency range different than the first range, applying filtering, and applying filtering to generate a second output signal, using filters that include a singly terminated filter section with additional circuit elements to form a transmission frequency zero in the stopband frequency range.

Abstract: An apparatus and method for applying signals into a filter circuit is disclosed. The apparatus includes a filter circuit that filters an input signal and outputs a signal in a first frequency range, and a filter circuit that filters the input signal and outputs a signal in a second frequency range that is different from the first frequency range, wherein the second filter circuit includes an interface circuit for inserting a signal used to receive the first frequency range signal. The method includes receiving a signal containing content from a first source in a first frequency range and content from a second source in a second frequency range, providing filtering to produce a signal containing the first content, providing filtering to produce a signal containing the second content, and applying a signal to second content signal processing circuitry, the signal provided used for receiving the content from the first source.

Abstract: Signal processing apparatus (100) such as a television signal receiver provides automatic gain control (AGC) in a manner that avoids excessive tuner gain reduction and compensates for interference from both analog and digital signals. According to an exemplary embodiment, the signal processing apparatus (100) includes a tuner (10) operative to tune an RF signal to generate an IF signal. A first filter (20) is operative to filter the IF signal to generate a filtered IF signal. An AGC detector (30) is operative to enable generation of an AGC signal for the tuner (10) responsive to the filtered IF signal. The AGC detector (30) includes a second filter (35) operative to attenuate a predetermined carrier frequency.

Abstract: In a switch mode power supply, a mains supply voltage source is coupled to a rectifier for producing an input supply voltage. The rectified input supply voltage is coupled unfiltered to an input of the SMPS. A switching power transistor having a controllable duty cycle is controlled by a duty cycle modulated signal for producing a regulated output supply voltage from the rectified input supply voltage. The periodic waveform of the mains supply voltage is used to establish the timings of the duty cycle modulated signal. In each cycle, current flow is initiated in the transistor, when the transistor is already fully turned on and a voltage developed between its main current conducting terminals is low or close to zero volts. When the output supply voltage attains the required level the transistor is turned off. Hysteresis is provided for preventing the transistor from turning on again in the same cycle, after it has been turned off.

Abstract: A technique for performing channel detection in a device such as a television signal receiver is capable of quickly determining the analog and/or digital broadcast channels available in a given area. According to an exemplary embodiment, a method for performing channel detection includes tuning a first frequency channel, determining whether a signal parameter associated with the first frequency channel exceeds a predetermined threshold, and enabling a first channel acquisition operation responsive to determining that the signal parameter exceeds the predetermined threshold.

Abstract: A system, apparatus and/or method provides frequency response adjustment of an RF input filter of an RF tuner based on impedance of an antenna system 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 by antenna system impedance presented at the antenna input that is other than a designed for impedance. Frequency response of an RF input filter for the RF tuner 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.