Communication systems adaptable to power line communications
View Patent ↗A communication system and method of operating the same that includes, in one embodiment, a transmit filter including a transmit filter capacitor, and a receive filter coupled to the transmit filter. The communication system also includes a switch, coupled to an auxiliary winding of a transformer and to the transmit filter capacitor, configured to alter an impedance of the transmit filter during a receive mode of operation of the communication system. In another embodiment, a transmitter is configured to receive an input data stream, and produce a control signal for a switch-mode power amplifier employing a predetermined data sequence selected by the input data stream thereto.
1. A communication system, comprising:
a transmit filter including a transmit filter capacitor;
a receive filter coupled to said transmit filter; and
a switch, coupled to an auxiliary winding of a transformer and to said transmit filter capacitor, configured to be open to alter an impedance of said transmit filter during a receive mode of operation of said communication system.
2. The communication system as recited in claim 1 , wherein said receive filter is coupled to said transmit filter at a common circuit node.
3. The communication system as recited in claim 1 , wherein said switch is coupled in parallel with said auxiliary winding of said transformer.
4. The communication system as recited in claim 1 , further comprising a transceiver configured to provide a signal to control said switch.
5. The communication system as recited in claim 1 , wherein said communication system is coupled to an alternating current power line.
6. The communication system as recited in claim 1 , wherein said switch is formed with a pair of back-to-back metal-oxide semiconductor field-effect transistors.
7. The communication system as recited in claim 1 , wherein said transformer is configured to galvanically isolate a power amplifier from a communication medium.
8. The communication system as recited in claim 7 , wherein said transmit filter comprises a transmit filter inductor coupled between an output of said power amplifier and a primary winding of said transformer.
9. The communication system as recited in claim 1 , wherein said auxiliary winding of said transformer is a secondary winding and said transmit filter capacitor is coupled thereto.
10. A method of operating a communication system, comprising:
filtering a signal to be transmitted with a transmit filter including a transmit filter capacitor during a transmit mode of operation of said communication system;
filtering a receive signal with a receive filter coupled to said transmit filter during a receive mode of operation of said communication system; and
altering an impedance of said transmit filter by opening a switch coupled to an auxiliary winding of a transformer and to said transmit filter capacitor during said receive mode of operation.
11. The method as recited in claim 10 , wherein said receive filter is coupled to said transmit filter at a common circuit node.
12. The method as recited in claim 10 , wherein said switch is coupled in parallel with said auxiliary winding of said transformer.
13. The method as recited in claim 10 , wherein altering said impedance of said transmit filter comprises providing a signal from a transceiver to control said switch.
14. The method as recited in claim 10 , wherein said communication system is coupled to an alternating current power line.
15. The method as recited in claim 10 , wherein said switch is formed with a pair of back-to-back metal-oxide semiconductor field-effect transistors.
16. The method as recited in claim 10 , wherein said transformer is configured to galvanically isolate a power amplifier from a communication medium.
17. The method as recited in claim 16 , wherein said transmit filter comprises a transmit filter inductor coupled between an output of said power amplifier and a primary winding of said transformer.
18. The method as recited in claim 10 , wherein said auxiliary winding of said transformer is a secondary winding and said transmit filter capacitor is coupled thereto.