Digital IF demodulator for video applications
AssigneeBroadcom Corporation
InventorsPieter Vorenkamp, Myles H. Wakayama, Steven Jaffe, Frank Carr, Arnoldus Venes, Peter R. Kinget, Daniel J. Marz, Thinh Nguyen
Life of this patent
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Abstract
An integrated communications system. A substrate having a receiver disposed on the substrate for converting a received signal to an IF signal, a digital IF demodulator disposed on the substrate and coupled to the receiver for converting the IF signal to a demodulated baseband signal, and a transmitter disposed on the substrate operating in cooperation with the receiver to establish a two way communications path.
Claims25
An integrated digital intermediate frequency (IF) demodulator, comprising:
- an analog input section configured to:
- receive an analog signal having a carrier frequency embedded within a desired channel of the analog signal, and
- amplify the received analog signal to provide an amplified analog signal via a first voltage gain amplifier (VGA);
- and
- convert, via an analog to digital converter (ADC), the amplified analog signal to a digital signal using a sampling frequency that is less than a frequency of the analog signal received by the ADC, the digital signal being frequency translated to an IF;
- an automatic gain control (AGC) circuit configured to generate a first output and a second output based on a magnitude of the frequency translated digital signal, the first output being provided to control a gain of the first VGA and the second output being provided to control a gain of a second VGA;
- a digital signal processing (DSP) block, coupled to the analog input section, configured to truncate a desired channel within the frequency translated digital signal and to frequency translate the desired channel within the frequency translated digital signal to a baseband frequency;
- and
- a substrate, wherein the DSP block and the analog input section are disposed on the substrate.
An integrated digital intermediate frequency (IF) demodulator, comprising:
- an analog input section configured to:
- receive an analog signal, including a video portion embedded onto a carrier frequency within a desired channel of the analog signal and a sound portion,
- amplify the received analog signal to provide an amplified analog signal via a first voltage gain amplifier (VGA);
- convert, via an analog to digital converter (ADC), the amplified analog signal to a digital representation using a sampling frequency that is less than a frequency of the analog signal received by the ADC, and
- frequency convert the digital representation of the analog signal to an IF;
- a first automatic gain control (AGC) circuit configured to generate a first output and a second output based on a magnitude of the frequency converted digital representation of the analog signal, the first output being provided to control a gain of the first VGA and the second output being provided to control a gain of a second VGA;
- a digital signal processing (DSP) block, coupled to the analog input section, configured to convert a desired channel within the digital representation of the analog signal to a baseband frequency and to separate the desired channel within the digital representation of the analog signal into the video portion and the sound potion;
- an analog output section, coupled to the DSP block, configured to convert the video portion and the sound portion to analog;
- and
- a substrate, wherein the DSP block and the analog output section are disposed on the substrate.
Dependencies are inferred from the claim text.