Modulation analyzer and level measurement device

• US 8,274,566 B2
• Filed: 10/09/2009
• Issued: 09/25/2012
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: PPC Broadband Incorporated (Belden Inc.)
• Original Assignee: John Mezzalingua Associates Incorporated
• Inventors: Kelma, David
• Primary Examiner(s): Harold, Jefferey
• Assistant Examiner(s): Rahman, Mustafizur
• Application Number:
  US12/576,278
• Publication Number:
  US 20110085045A1
• Time in Patent Office: 1,082 Days
• Field of Search: 348/180, 348/192, 348/194, 348/354, 348/356, 348/425, 348/500, 348/521, 348/725
• US Class Current: 348/180
• CPC Class Codes: H04N 17/00 Diagnosis, testing or measuring for television systems or their details

Abstract

A method is provided for determining a modulation of a CATV channel, the modulation being one of a digital modulation and an analog modulation. The method includes passing at least a portion of a tuner output from a tuner to a RF detector, and passing a RF detector output from the RF detector to a sync detector. The method further includes attenuating at least a portion of a sync detector output to create a remaining portion of the sync detector output, and passing the remaining portion of the sync detector output to a peak detector. The method further includes passing an output of the peak detector to a subsequent device, the output of the peak detector indicating whether the modulation of the CATV channel.

Claims

1. A modulation analyzer and level measurement device for use with a CATV system, the device comprising:

a tuner;

a band pass filter directly connected to the tuner, wherein the band pass filter is connected electrically downstream from the tuner;

an RF detector directly connected to the band pass filter, wherein the band pass filter is connected electrically downstream from the band pass filter, and wherein the RF detector is configured to convert a frequency domain voltage stream to a time domain voltage stream;

a sync detector directly connected to the RF detector, wherein the sync detector is connected electrically downstream from the RF detector, and wherein the sync detector is configured to receive the time domain voltage stream and extract timing information from the time domain voltage stream; and

a peak detector connected electrically downstream the sync detector, wherein the peak detector is configured to generate a consistent voltage stream when the sync detector provides a voltage stream comprising synchronous voltages.

2. The device of claim 1 further comprising:

a low frequency level detector connected electrically downstream the band pass filter;

a DC shift amplifier connected electrically downstream the low frequency amplifier; and

a high gain amplifier connected electrically downstream the DC shift amplifier.

3. The device of claim 1 further comprising:

a low frequency level detector connected electrically downstream the band pass filter;

a DC shift amplifier connected electrically downstream the low frequency amplifier; and

a low-gain amplifier connected electrically downstream the DC shift amplifier.

4. The device of claim 2 further comprising a low-gain amplifier connected electrically downstream the DC shift amplifier.

5. The device of claim 1 further comprising a low pass filter connected electrically between the sync detector and the peak detector.

6. The device of claim 2 further comprising a first voltage source connected to the DC shift amplifier.

7. The device of claim 3 further comprising a second voltage source connected to the low-gain amplifier.

8. The device of claim 4 further comprising a microprocessor connected electrically downstream each of the DC shift amplifier, low-gain amplifier, and the peak detector.

10. The device of claim 1 further comprising a fixed signal level adjustment device may connected between an RF connector and the tuner, wherein the fixed signal level adjustment device is configured to prevent the RF connector from drawing too much power from a connected source, and wherein the fixed signal level adjustment device is further configured to be sized to provide the tuner with a coupled downstream bandwidth comprising a specified amount of power for the tuner.

9. A method for determining a modulation of a CATV channel, the modulation being one of a digital modulation and an analog modulation, the method comprising:

passing at least a portion of a tuner output from a tuner, through a band pass filter, to a RF detector, wherein the band pass filter directly connected between the tuner and the RF detector;

generating, by the RF detector, a RF detector output by converting a frequency domain voltage stream to a time domain voltage stream;

passing the RF detector output from the RF detector to a sync detector directly connected to the RF detector;

extracting, by the sync detector, timing information from the time domain voltage stream;

attenuating at least a portion of a sync detector output to create a remaining portion of the sync detector output;

passing the remaining portion of the sync detector output to a peak detector;

generating, by the peak detector, a consistent voltage stream when the sync detector provides a voltage stream comprising synchronous voltages; and

passing an output of the peak detector to a subsequent device, the output of the peak detector indicating whether the modulation of the CATV channel.