Power Divider Networks for Cable Television Networks that Include Multimedia Over Coax Bypass Circuits and Signal Amplifiers that Include Such Power Divider Networks

• US 20100162340A1
• Filed: 07/28/2009
• Published: 06/24/2010
• Est. Priority Date: 12/18/2008
• Status: Active Grant

• Current Assignee: Digicomm International LLC
• Original Assignee: Commscope Inc of North Carolina (CommScope Holding Company, Inc.)
• Inventors: Riggsby, Robert Ryan
• Granted Patent: US 8,397,271 B2
• Time in Patent Office: Days
• US Class Current: 725/127
• CPC Class Codes: H04B 3/04 Control of transmission; Equalising
• CPC Class Codes: H04N 7/102 Circuits therefor, e.g. noise reducers, equalisers, amplifiers H04N7/108 takes precedence

Abstract

RF signal amplifiers for cable television networks are provided that include an RF input port. a power amplifier coupled to the RF input port and a power divider having an input that is coupled to an output of the power amplifier. The power divider includes a first directional coupler that is coupled to an output of the power amplifier. The directional coupler includes a first output branch and a second output branch. A first bypass circuit is coupled between the first and second output branches of the first directional coupler. A response of the power divider includes a null that substantially blocks signals received at the input of the power divider from passing to outputs of the power divider in a subset of frequencies within the range of 5 MHz to 1550 MHz. These RF signal amplifiers may provide improved performance, robustness and reliability when used in MOCA networks.

Claims

1. A RF signal amplifier for a cable television network, comprising:

an RF input port;

a power amplifier coupled to the RF input port;

a power divider having an input that is coupled to an output of the power amplifier and first and second outputs, the power divider comprising

a first directional coupler that has a first output branch and a second output branch; and

a first bypass circuit coupled between the first and second output branches of the first directional coupler,

wherein a response of the power divider includes a null that substantially blocks signals received at the input of the power divider from passing to the first or second outputs of the power divider in a subset of frequencies within the range of 5 MHz to 1550 MHz.

2. The RF signal amplifier of claim 1, wherein the center frequency of the null is located in between 870 MHz and 1150 MHz.

3. The RF signal amplifier of claim 1, wherein the center frequency of the null is located in between 1002 MHz and 1100 MHz.

4. The RF signal amplifier of claim 3, wherein the power divider further includes an isolation circuit that is provided between the first output and the second output of the power divider that is configured to block signals in the 5 MHz to 1002 MHz frequency band.

5. The RF signal amplifier of claim 4, wherein the first bypass circuit comprises a first bandpass/high pass filter that is configured to pass signals in the 1150 MHz to 1550 MHz frequency band.

6. The RF signal amplifier of claim 5, wherein the power divider further comprises:

a second directional coupler that is coupled to the first output branch of the first directional coupler;

a third directional coupler that is coupled to the second output branch of the first directional coupler.

7. The RF signal amplifier of claim 6, further comprising:

a second bandpass/high pass filter coupled between a first output branch and a second output branch of the second directional coupler; and

a third bandpass/high pass filter coupled between a first output branch and a second output branch of the third directional coupler.

8. The RF signal amplifier of claim 7, further comprising:

a fourth directional coupler that is coupled to the first output branch of the second directional coupler;

a fifth directional coupler that is coupled to the second output branch of the second directional coupler;

a sixth directional coupler that is coupled to the first output branch of the third directional coupler;

a seventh directional coupler that is coupled to the second output branch of the third directional coupler;

a fourth bandpass/high pass filter coupled between a first output branch and a second output branch of the fourth directional coupler;

a fifth bandpass/high pass filter coupled between a first output branch and a second output branch of the fifth directional coupler.

a sixth bandpass/high pass filter coupled between a first output branch and a second output branch of the sixth directional coupler; and

a seventh bandpass/high pass filter coupled between a first output branch and a second output branch of the seventh directional coupler.

9. The RF signal amplifier of claim 8, wherein the power amplifier is part of a first communication path between the RF input port and the power divider, and wherein the RF signal amplifier further comprises a second non-amplified, non-interruptible communication path between the RF input port and a separate RF output port.

10. The RF signal amplifier of claim 9, further comprising:

a power input for receiving electrical power; and

a selective termination circuit that is configured to pass signals between the RF input port and a plurality of RF output ports over the first communication path when electrical power is received at the power input, and that is further configured to terminate the first communication path to a matched termination when an electrical power feed to the power input is interrupted.

11. The RF signal amplifier of claim 10, wherein the selective termination circuit comprises a relay having an input terminal, a first output terminal and a second output terminal, wherein the first output terminal of the relay is coupled to the power amplifier and the second output terminal of the relay is connected to a resistor that is terminated to a ground voltage, the RF signal amplifier further comprising a directional coupler having an input that is connected to the RF input port, a first output that is connected to the input terminal of the relay and a second output that is connected to the second non-interruptible communication path.

12. The bi-directional RF signal amplifier of claim 10, wherein the power amplifier comprises a first power amplifier, and wherein the first communication path includes a forward path from the RF input port to the power divider and a reverse path from the power divider to the RF input port, and wherein the reverse path includes a second power amplifier, and wherein the first communication path further comprises a diplexer that is between the first output terminal of the relay and the first power amplifier and a triplexer that is between the first power amplifier and the power divider.

13. An RF signal amplifier for a cable television network, comprising:

an RF input port;

a power amplifier coupled to the RF input port;

a power divider network comprising;

a first directional coupler coupled to an output of the power amplifier, the first directional coupler including a first output and a second output; and

a filter coupled between the first output and the second output of the first directional coupler, wherein the filter is configured to block signals in the 5 MHz to 1002 MHz frequency band and to pass signals in at least the 1150 MHz to 1550 MHz frequency band,

wherein the power divider network blocks signals in at least a portion of the 870 MHz to 1150 MHz frequency band.

14. The RF signal amplifier of claim 13, wherein the power divider network further includes a plurality of RF output ports, and wherein the power divider network further comprises:

a second directional coupler that is coupled to the first output of the first directional coupler;

a third directional coupler that is coupled to the second output of the first directional coupler;

a second filter coupled between a first output and a second output of the second directional coupler that is configured to block signals in the 5 MHz to 1002 MHz frequency band and to pass signals in the 1150 MHz to 1550 MHz frequency band; and

a third filter coupled between a first output and a second output of the third directional coupler that is configured to block signals in the 5 MHz to 1002 MHz frequency band and to pass signals in the 1150 MHz to 1550 MHz frequency band.

15. The RF signal amplifier of claim 14, further comprising:

a fourth directional coupler that is coupled to the first output of the second directional coupler;

a fifth directional coupler that is coupled to the second output of the second directional coupler;

a sixth directional coupler that is coupled to the first output of the third directional coupler;

a seventh directional coupler that is coupled to the second output of the third directional coupler;

a fourth filter coupled between a first output and a second output of the fourth directional coupler that is configured to block signals in the 5 MHz to 1002 MHz frequency band and to pass signals in the 1150 MHz to 1550 MHz frequency band;

a fifth filter coupled between a first output and a second output of the fifth directional coupler that is configured to block signals in the 5 MHz to 1002 MHz frequency band and to pass signals in the 1150 MHz to 1550 MHz frequency band;

a sixth filter coupled between a first output and a second output of the sixth directional coupler that is configured to block signals in the 5 MHz to 1002 MHz frequency band and to pass signals in the 1150 MHz to 1550 MHz frequency band; and

a seventh filter coupled between a first output and a second output of the seventh directional coupler that is configured to block signals in the 5 MHz to 1002 MHz frequency band and to pass signals in the 1150 MHz to 1550 MHz frequency band.

16. The RF signal amplifier of claim 15, wherein the power amplifier is part of a first communication path between the RF input port and the power divider network, and wherein the RF signal amplifier further comprises a second non-amplified, non-interruptible communication path between the RF input port and a separate RF output port.

17. The RF signal amplifier of claim 16, further comprising:

a power input for receiving electrical power; and

a selective termination circuit that is configured to pass signals between the RF input port and the plurality of RF output ports over the first communication path when electrical power is received at the power input and that is further configured to terminate the first communication path to a matched termination when an electrical power feed to the power input is interrupted.

18. An RF signal amplifier for a cable television network, comprising:

an RF input port;

a power amplifier coupled to the RF input port; and

a power divider network that includes at least a first directional coupler that is coupled to an output of the power amplifier, a second directional coupler and a third directional coupler, wherein a first filter is coupled between a first output and a second output of one of the first, second or third directional couplers, wherein the first filter is configured to block signals in the 5 MHz to 1002 MHz frequency band and to pass signals in at least the 1150 MHz to 1550 MHz frequency band.

19. A method of passing a MOCA signal from a first device to a second device, the method comprising:

receiving the MOCA signal from the first device at a first output of a first directional coupler of a power divider network of an RF signal amplifier;

passing the signal from the first output of the first directional coupler to an input of the first directional coupler that is coupled to a first output of a second directional coupler of the power divider network;

passing the signal from the first output of the second directional coupler to a second output of the second directional coupler via a bypass circuit that passes signals in at least the 1150 MHz to 1550 MHz frequency band while providing at least 25 dB of isolation with respect to signals in a CATV frequency band;

passing the signal from the second output of the second directional coupler to an input of a third directional coupler that is coupled to the second output of a second directional coupler of the power divider network;

passing the signal from the input of a third directional coupler to a first output of the third directional coupler; and

passing the signal to the second device.

20. A RF power divider network, comprising:

an RF input port;

a first directional coupler coupled to the RF input port, the first directional coupler including a first output and a second output;

an isolation circuit provided between the first output and the second output of the first directional coupler that is configured to block signals in the 5 MHz to 1002 MHz frequency band; and

a first bypass circuit coupled between the first and second outputs of the first directional coupler;

wherein the first bypass circuit comprises a first filter that is configured to pass signals in the 1150 MHz to 1550 MHz frequency band.

21. The RF power divider network of claim 20, further comprising:

a second directional coupler that is coupled to the first output of the first directional coupler;

a second bandpass/high pass filter coupled between a first output and a second output of the second directional coupler;

a third directional coupler that is coupled to the second output of the first directional coupler; and

a third bandpass/high pass filter coupled between a first output and a second output of the third directional coupler.