Active replica transformer hybrid

• US 7,804,904 B1
• Filed: 03/24/2005
• Issued: 09/28/2010
• Est. Priority Date: 05/23/2000
• Status: Expired due to Fees

• Current Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Sutardja, Sehat
• Primary Examiner(s): PHU, PHUONG M
• Application Number:
  US11/089,010
• Time in Patent Office: 2,014 Days
• Field of Search: 375219-222, 375/257, 375/258, 375/285, 375/346, 375/350, 370/286, 370289-291, 37940601-40608
• US Class Current: 375/258
• CPC Class Codes: H03M 1/0626 by filtering
• CPC Class Codes: H03M 1/66 Digital/analogue converters H03M1/001 – H03M1/10 take precedence
• CPC Class Codes: H04L 25/028 Arrangements specific to the transmitter end

Abstract

A communication circuit includes a near end transmitter, a hybrid having an input in communication with an output of the near end transmitter, and a near end adjustable load replication transmitter having an adjustable load. The communication circuit further includes a subtractor configured to subtract an output from the near end adjustable load replication transmitter from the output from the near end transmitter and the hybrid. The communication circuit further includes a near end receiver responsive to an output of the subtractor and a calibration circuit configured to adjust the adjustable load against a reference load.

Claims

1. A communication circuit comprising:

a near end transmitter;

a hybrid having an input in communication with an output of the near end transmitter;

a near end adjustable load replication transmitter having an adjustable load;

a subtractor configured to subtract an output from the near end adjustable load replication transmitter from the output from the near end transmitter and the hybrid;

a near end receiver responsive to an output of the subtractor; and

a calibration circuit configured to adjust the adjustable load against a reference load.

2. The communication circuit of claim 1, wherein the near end adjustable load replication transmitter comprises a current generator in communication with the adjustable load.

3. The communication circuit of claim 1, wherein the near end adjustable load replication transmitter comprises an adjustable current generator in communication with a load.

4. The communication circuit of claim 1, wherein the near end adjustable load replication transmitter is configured to maximize amplitude matching between the near end transmitter and the near end adjustable replication transmitter.

5. The communication circuit of claim 1, wherein the near end adjustable load replication transmitter comprises a voltage multiplier.

6. The communication circuit of claim 1, comprising:

an adjustable capacitive load in communication with the near end adjustable load replication transmitter and configured to maximize signal delay matching between the near end transmitter and the near end adjustable load replication transmitter.

27. The communication circuit of claim 1, wherein the subtractor receives a transmitted signal generated by the near end transmitter directly from the output of the near end transmitter.

28. The communication circuit of claim 1, wherein the near end adjustable load replication transmitter replicates an amplitude of a transmitted signal generated by the near end transmitter.

7. A communication circuit comprising:

a near end transmitter;

a hybrid having an input in communication with an output of the near end transmitter;

a near end adjustable load replication transmitter having an adjustable load;

a subtractor configured to subtract an output from the near end adjustable load replication transmitter from the output from the near end transmitter and the hybrid;

a near end receiver responsive to an output of the subtractor; and

an adjustable capacitive load in communication with the near end adjustable load replication transmitter, wherein the adjustable capacitive load adjusts signal delays of transmitted and replication signals generated by the near end transmitter and the near end adjustable load replication transmitter, respectively.

8. The communication circuit of claim 7, comprising:

an adaptive control circuit,

wherein the adjustable capacitive load is responsive to the adaptive control circuit.

9. A communication method, comprising the steps of:

(a) transmitting a transmitted signal;

(b) combining the transmitted signal with a received signal from a channel;

(c) generating a replication signal using a near end adjustable load replication transmitter having an adjustable load that is adjusted against a reference load;

(d) adjusting the replication signal;

(e) subtracting the adjusted replication signal from the transmitted and received signals to generate an output signal; and

(f) receiving the output signal from step (e).

10. The communication method of claim 9, wherein step (d) comprises the steps of:

(d1) adjusting a current; and

(d2) adjusting the adjustable load.

11. The communication method of claim 9, wherein step (d) comprises the step of:

(d1) adjusting a current.

12. The communication method of claim 9, wherein step (d) comprises the step of:

(d1) maximizing amplitude matching between the replication signal and the transmitted signal.

29. The communication method of claim 9, wherein step (d) comprises the step of:

(d1) replicating an amplitude of the transmitted signal.

13. A communication circuit, comprising:

a near end circuit comprising;

a near end transmitter;

a near end hybrid having a first terminal in communication with an output of the near end transmitter and a second terminal;

a near end adjustable load replication transmitter having an adjustable load;

a near end subtractor configured to subtract an output from the near end adjustable load replication transmitter from the output from the near end transmitter and the near end hybrid; and

a near end receiver responsive to an output of the near end subtractor; and

a calibration circuit configured to adjust the adjustable load against a reference load; and

a far end circuit comprising;

a far end transmitter;

a far end hybrid having a third terminal in communication with an output of the far end transmitter and a fourth terminal in communication with the second terminal of the near end hybrid;

a far end adjustable load replication transmitter having an adjustable load;

a far end subtractor configured to subtract an output from the far end adjustable load replication transmitter from the output from the far end transmitter and the far end hybrid; and

a far end receiver responsive to an output of the far end subtractor; and

a calibration circuit configured to adjust the adjustable load against a reference load.

14. A communication method, comprising the steps of:

(a) transmitting a first signal;

(b) combining the first signal with a second signal from a channel;

(c) generating a first replication signal using a first near end adjustable load replication transmitter having an adjustable load that is adjusted against a reference load;

(d) adjusting the first replication signal;

(e) subtracting the adjusted first replication signal from the first and second signals to generate a first output signal;

(f) receiving the first output signal from step (e);

(g) transmitting the second signal;

(h) combining the second signal with the first signal from the channel;

(i) generating a second replication signal using a second near end adjustable load replication transmitter having an adjustable load that is adjusted against a reference load;

(j) adjusting the second replication signal;

(k) subtracting the adjusted second replication signal from the first and second signals to generate a second output signal; and

(l) receiving the second output signal from step (k).

15. A communication circuit, comprising:

a near end transmitter comprising at least one near end current source; and

a near end replication transmitter comprising;

at least one replication current source arranged in series and configured to generate a replication voltage across a replication resistance,

wherein the at least one replication current source corresponds to a respective one of the at least one near end current source, and

wherein the at least one replication current source is in electrical communication with a respective one of the at least one near end current source; and

wherein each of the at least one near end current source comprises;

a near end transistor, and

wherein each of the at least one replication current source comprises;

a replication current transistor,

wherein a gate of a corresponding near end transistor is coupled directly to a gate of a respective near end replication transistor.

16. The communication circuit of claim 15, wherein the replication voltage is scaled in accordance with a size of the replication resistance and a size of the at least one replication current transistor.

17. The communication circuit of claim 15, comprising:

a hybrid having an input in communication with an output of the near end transmitter;

a subtractor configured to subtract an output from the near end replication transmitter from the output from the near end transmitter and an output of the hybrid; and

a near end receiver responsive to an output of the subtractor.

18. The communication circuit of claim 17, wherein the hybrid comprises:

an output resistance; and

a transformer.

19. An Ethernet transceiver, comprising:

a near end transmitter comprising at least one near end current source; and

a near end replication transmitter comprising;

at least one replication current source arranged in series and configured to generate a replication voltage across a replication resistance,

wherein the at least one replication current source corresponds to a respective one of the at least one near end current source, and

wherein the at least one replication current source is in electrical communication with a respective one of the at least one near end current source; and

wherein each of the at least one near end current source comprises;

a near end transistor, and

wherein each of the at least one replication current source comprises;

a replication current transistor,

wherein a gate of a corresponding near end transistor is coupled directly to a gate of a respective near end replication transistor.

20. The Ethernet transceiver of claim 19, wherein the replication voltage is scaled in accordance with a size of the replication resistance and a size of the at least one replication current transistor.

21. The Ethernet transceiver of claim 19, comprising:

a hybrid having an input in communication with an output of the near end transmitter;

a subtractor configured to subtract an output from the near end replication transmitter from the output from the near end transmitter and an output of the hybrid; and

a near end receiver responsive to an output of the subtractor.

22. The Ethernet transceiver of claim 21, wherein the hybrid comprises:

an output resistance; and

a transformer.

23. The Ethernet transceiver of claim 21, wherein the Ethernet transceiver is compliant with I.E.E.E. 802.3ab.

24. A transceiving method, comprising the steps of:

(a) generating a near end signal for transmission via a transceiver by;

(a1) generating a plurality of near end currents; and

(a2) summing the generated plurality of near end currents generated in step (a1); and

(b) generating a replication signal by;

(b1) generating a plurality of replication currents based on the generated plurality of near end currents generated in step (a1); and

(b2) summing the generated plurality of replication currents generated in step (b1).

25. The transceiving method of claim 24, wherein step (b) comprises the step of:

(b3) converting the summed replication currents summed in step (b2) to a voltage.

26. The transceiving method of claim 24, comprising the steps of:

(c) combining a received signal with the near end signal generated in step (a);

(d) subtracting the replication signal in step (b) from the combined signal in step (c) to generate an output; and

(e) receiving the output from step (d).

30. A communication method comprising:

(a) transmitting a transmitted signal;

(b) combining the transmitted signal with a received signal from a channel;

(c) generating a replication signal using a near end adjustable load replication transmitter having an adjustable load;

(d) adjusting the replication signal;

(e) subtracting the adjusted replication signal from the transmitted and received signals to generate an output signal; and

(f) receiving the output signal from step (e);

wherein step (d) comprises the step of;

(d1) adjusting signal delays of the transmitted signal and the replication signal.