Power divider networks for cable television networks that include multimedia over coax bypass circuits and signal amplifiers that include such power divider networks
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.
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 substantially block signals across the entire 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;
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.
7. The RF signal amplifier of claim 6 , 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;
wherein the fourth through seventh directional couplers each include first and second output branches and wherein the fourth through seventh directional couplers do not include bandpass or high pass filters between their respective first and second output branches.
8. The RF signal amplifier of claim 7 , 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, and
wherein the RF signal amplifier is configured to pass signals between an output of the power divider and the separate RF output port in the 1150 MHz to 1550 MHz frequency band.
9. The RF signal amplifier of claim 8 , 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.
10. The RF signal amplifier of claim 9 , 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.
11. The bi-directional RF signal amplifier of claim 9 , 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.
12. The RF signal amplifier of claim 1 , further comprising a triplexer coupled between the power amplifier and the power divider, the triplexer including a filter that passes signals in at least part of the 1150 MHz to 1550 MHz frequency band.
13. The RF signal amplifier of claim 1 , wherein the RF signal amplifier is further configured to pass signals in at least part of the 1150 MHz to 1550 MHz frequency band to the RF input port.
14. The RF signal amplifier of claim 1 , wherein the center frequency of the null is located outside a pass band of the first bypass circuit.
15. 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 an input, 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 from passing from the input of the first directional coupler to either the first or second output of the first directional coupler.
16. The RF signal amplifier of claim 15 , 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.
17. The RF signal amplifier of claim 16 , 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.
18. The RF signal amplifier of claim 17 , 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.
19. 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 that is configured to pass signals in the 1150 MHz to 1550 MHz frequency band;
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 bypass circuit coupled between the first and second outputs of the second directional coupler that is configured to pass signals in the 1150 MHz to 1550 MHz frequency band;
a third bypass circuit coupled between the first and second outputs of the third directional coupler that is configured to pass signals in the 1150 MHz to 1550 MHz frequency band.
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;
wherein the fourth through seventh directional couplers do not include bypass circuits coupled between their respective first and second outputs.
20. An RF signal amplifier for a cable television network, comprising:
an RF input port;
a power divider network that includes at least first and second RF output ports;
a first communication path between the RF input port and the power divider network;
a second non-amplified, non-interruptible communication path between the RF input port and a third RF output port,
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 power divider network 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,
wherein the first communication path includes a forward path from the RF input port to the power divider network that includes a first power amplifier and a reverse path from the power divider network to the RF input port that includes a second power amplifier, a diplexer that is between the RF input port and the first power amplifier and a triplexer that is between the first power amplifier and the power divider network, and
wherein the power divider network comprises at least
a first directional coupler coupled to an output of the power amplifier, the first directional coupler including an input, 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 first directional coupler blocks signals in at least a portion of the 870 MHz to 1150 MHz frequency band from passing from the input of the directional coupler to either the first or second outputs of the directional coupler.
21. The RF signal amplifier of claim 20 , 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 first 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 second 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.
22. The RF signal amplifier of claim 21 , further comprising diplexer coupled between the RF input port and the second directional coupler.