Set-top box with out-of band modem and cable modem

• US 7,043,750 B2
• Filed: 03/22/2001
• Issued: 05/09/2006
• Est. Priority Date: 04/14/2000
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Ina, Norihisa
• Primary Examiner(s): Srivastava, Vivek
• Assistant Examiner(s): Sheleheda, James
• Application Number:
  US09/815,100
• Publication Number:
  US 20020083466A1
• Time in Patent Office: 1,874 Days
• Field of Search: 725/111, 725/110, 725/131, 725/151
• US Class Current: 725/131
• CPC Class Codes: H03H 7/46 Networks for connecting several sources or loads, working on different frequencies or frequency bands, to a common load or source for use in multiplex transmission systems H04J1/00
• CPC Class Codes: H04H 20/80 having frequencies in two or more frequency bands, e.g. medium wave and VHF
• CPC Class Codes: H04N 21/42676 for modulating an analogue carrier signal to encode digital information or demodulating it to decode digital information, e.g. ADSL or cable modem
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/6168 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 7/102 Circuits therefor, e.g. noise reducers, equalisers, amplifiers H04N7/108 takes precedence
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications

Abstract

A circuit arrangement for combining signals in a cable set-top box or television receiver. An out-of-band upstream amplifier and a cable modem upstream amplifier have their outputs combined at a combiner before being passed to the cable through a diplexer. The output of the diplexer provides incoming signals for an in-band tuner, a cable modem tuner and an out-of-band tuner that can be passed through a low noise amplifier before passing through a three-way splitter to divide the signals to each of the tuners.

Claims

1. An apparatus for combining upstream and downstream signals in a television set-top box, comprising:

a cable interface interfacing to a cable television cable;

a diplexer coupled to the television cable interface at a diplexer port, the diplexer having a diplexer input for receiving upstream signals and a diplexer output for providing downstream signals;

a combiner having an output coupled to the diplexer input, and having a first input receiving a first output from a first upstream modem output, and having a second input receiving a second output from a second upstream modem output;

wherein the first upstream modem output comprises an out-of-band modem output, and wherein the second upstream modem output comprises a cable modem output;

a splitter having an input coupled to the diplexer output, and having a first output providing signals to a first tuner, and having a second output providing signals to a second tuner, and having a third output providing signals to a third tuner, wherein the first tuner comprises an inband tuner for tuning television programming, wherein the second tuner comprises an out-of-band tuner for tuning out-of-band data, and wherein the third tuner comprises a cable modem tuner; and

a wideband low noise amplifier disposed between the diplexer output and the splitter input.

2. The apparatus according to claim 1, wherein the splitter comprises a transformer having a primary winding and a secondary winding, with center taps for both the primary winding and the secondary winding, the center taps being connected together and grounded through a capacitor, and wherein the primary winding serves as the splitter input and the secondary winding serves as the splitter outputs, with a first end of the primary winding being grounded and a first end of the secondary winding serving as the first output and the second end of the secondary winding serving as the second output.

3. The apparatus according to claim 2, further comprising a filter disposed between the amplifier and the splitter.

4. The apparatus according to claim 3, wherein the filter comprises a high pass filter.

5. The apparatus according to claim 4, wherein the high pass filter has a pass band starting at a frequency less than 54 Mhz.

6. The apparatus according to claim 1, further comprising a filter disposed between the diplexer input and the combiner.

7. The apparatus according to claim 6, wherein the filter comprises a low pass filter.

8. The apparatus according to claim 7, wherein the low pass filter has a bandwidth of approximately 42 Mhz.

9. The apparatus according to claim 6, wherein the filter comprises a bandpass filter.

10. The apparatus according to claim 9, wherein the filter has a pass band between 5 Mhz and 42Mhz.

11. The apparatus according to claim 1, wherein the first tuner tunes to signals between 54 Mhz and 860 Mhz.

12. The apparatus according to claim 1, wherein the second tuner tunes to signals between 70 Mhz and 130 Mhz.

13. The apparatus according to claim 1, wherein the third tuner tunes to signals between 88 MHz and 860 Mhz.

14. The apparatus according to claim 1, wherein the oat-of-band modem operates between 5 Mhz and 42 Mhz.

15. The apparatus according to claim 1, wherein the cable modem operates between 5 Mhz and 42 Mhz.

16. The apparatus according to claim 1, further comprising a filter disposed between the diplexer and the splitter.

17. The apparatus according to claim 16, wherein the filter comprises a high pass filter.

18. An apparatus for combining upstream and downstream signals in a television Set-Top Box, comprising:

a cable interface for interfacing to a cable television cable;

a diplexer coupled to the television cable interface at a diplexer port, the diplexer having a diplexer input for receiving upstream signals and a diplexer output for providing downstream signals;

a wideband low noise amplifier receiving the downstream signals from the diplexer to produce, an amplified output;

a high pass filter, having a pass baud above 54 Mhz, receiving the amplified output and producing a high pass filtered output;

a combiner having an output, and having a first input receiving a first output from an out-of-band modem output, end having a second input receiving a second output from a cable modem output;

a low pass filter receiving the combiner output and providing a low pass filtered output to the diplexer input;

a splitter having an input receiving the high pass filtered output, and having a first output providing signals to an inband tuner, and having a second output providing signals to an out-of-band tuner, and having a third output providing signals to a cable modem tuner;

wherein the splitter comprises a transformer having a primary winding and a secondary winding, wit center taps for both the primary winding and the secondary winding, the center taps being connected together and grounded through a capacitor, and wherein the primary winding serves as the splitter input and the secondary winding serves as the splitter outputs, with a first end of the primary winding being grounded and a first end of the secondary winding serving as the first output and the second end of the secondary winding serving as the second output;

wherein the low pass filter has a bandwidth of approximately 42 Mhz;

wherein the in-band tuner tunes to signals between 54 Mhz and 860 Mhz;

wherein the out-of-band tuner tunes to signals between 70 Mhz and 130 Mhz;

wherein the cable modem tuner tunes to signals between 88 Mhz and 860 Mhz;

wherein the out-of-band modem operates between 5 Mhz and 42 Mhz; and

wherein the cable modem operates between 5 Mhz and 42 Mhz.