RECEIVER ARCHITECTURES UTILIZING COARSE ANALOG TUNING AND ASSOCIATED METHODS

摘要

Receiver architectures and associated methods are disclosed that provide initial analog coarse tuning (102) of desired channels (108) within a received signal spectrum (107), such as a set-top box signal spectrum for satellite communications. These architectures provide significant advantages over prior direct down-conversion (DDC) architectures and low intermediate-frequency (IF) architectures, particularly where two tuners are desired on the same integrated circuit. Rather than using a low-IF frequency or directly converting the desired channel frequency to DC, initial coarse tuning provided by analog coarse tuning circuitry (102) allows for a conversion to a frequency range around DC. This coarse tuning circuitry can be implemented, for example, using a large-step local oscillator (LO) (106) that provides a coarse tune analog mixing signal (116). Once mixed down, the desired channel may then be fine-tuned through digital processing (104), such as through the use of a wide-band analog-to-digital converter (ADC) or a narrow-band tunable bandpass ADC.