Differential signal measurement system and method

Patent metadata

Field	Value
Publication number	US-10877092-B2
Application number	US-201815911904-A
Country	US
Kind code	B2
Filing date	Mar 5, 2018
Priority date	Mar 5, 2018
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

A differential signal measurement system is provided. The differential signal measurement system includes a measurement device, with at least one differential signal input, a differential connection interface configured to connect the at least one differential signal input of the measurement device to a device under test, and a differential signal source, with at least one differential signal output, configured to generate at least one differential output signal. The differential connection interface is further configured to pass the at least one differential output signal to the at least one differential signal input of the measurement device, and the measurement device is configured to capture the at least one differential output signal.

First claim

What is claimed is:

1. A differential signal measurement system comprising:
a measurement device comprising at least one differential signal input;
a differential connection interface configured to connect the at least one differential signal input of the measurement device to a device under test;
a differential signal source, comprising at least one differential signal output, configured to generate at least one differential output signal;
a first differential filter; and
a second differential filter; and
wherein the differential connection interface is further configured to pass the at least one differential output signal to the at least one differential signal input of the measurement device,
wherein the measurement device is configured to capture the at least one differential output signal, and
wherein the measurement device is further configured to perform a dedicated symmetry adjustment by using one or more of the first differential filter and the second differential filter.

2. The measurement system according to claim 1 , wherein the first differential filter is configured to be connected to the at least one differential signal input of the measurement device, and to compensate signal errors caused by one or more of the differential connection interface and the at least one differential signal input, with respect to the at least one differential output signal captured by the measurement device.

3. The measurement system according to claim 1 , wherein the measurement device comprises one or more of an oscilloscope, a logic analyzer, and a spectrum analyzer.

4. The measurement system according to claim 1 , wherein the at least one differential signal input comprises two single-ended signal inputs, and/or the at least one differential signal output comprises two single-ended signal outputs.

5. The measurement system according to claim 4 , wherein the two single-ended signal inputs comprise one or more of a different return loss and a different insertion loss.

6. The measurement system according to claim 1 , wherein the differential connection interface comprises two cables comprising one of twisted-pair cables and triax cables.

7. The measurement system according to claim 1 , wherein the at least one differential output signal comprises one or more of at least one differential pulse and at least one sine-wave, and/or the at least one differential output signal comprises two parallel or sequential single-ended signals with known time relation.

8. The measurement system according to claim 1 , wherein the at least one differential output signal comprises one or more of at least one differential signal portion, at least one common-mode signal portion, at least one positive single-ended signal portion, and at least one negative single-ended signal portion.

9. The measurement system according to claim 2 :
wherein the first differential filter is configured based on at least one filter coefficient; and
wherein the measurement device is further configured to measure a positive signal portion and a negative signal portion of at least one differential input signal at the at least one differential signal input, to determine an individual error with respect to the positive signal portion and the negative signal portion of the at least one differential input signal, and to minimize the individual error by adjusting the at least one filter coefficient.

10. The measurement system according to claim 2 :
wherein the first differential filter is configured based on at least one filter coefficient; and
wherein the measurement device is further configured to measure a common-mode signal portion of at least one differential input signal at the at least one differential signal input, to determine an individual error with respect to the common-mode signal portion of the at least one differential input signal, and to minimize the individual error by adjusting the at least one filter coefficient.

11. The measurement system according to claim 2 ,
wherein the first differential filter is configured based on at least one filter coefficient,
wherein the second differential filter is configured based on at least one additional filter coefficient, and
wherein the measurement device is further configured to measure a positive signal portion and a negative signal portion of at least one differential input signal at the at least one differential signal input, and to measure a common-mode signal portion of the at least one differential input signal at the at least one differential signal input.

12. The measurement system according to claim 11 , wherein the measurement device is further configured to determine an individual error with respect to the positive signal portion and the negative signal portion of the at least one differential input signal, to determine an additional individual error with respect to the common-mode signal portion of the at least one differential input signal, and to minimize the individual error and the additional individual error by adjusting the at least one filter coefficient and the at least one additional filter coefficient.

13. A differential signal measurement method comprising:
generating, by a differential signal source via at least one differential signal output, at least one differential output signal;
forwarding the at least one differential output signal to at least one differential signal input of a measurement device via a differential connection interface;
capturing, by the measuring device, the at least one differential output signal; and
performing a dedicated symmetry adjustment by using one or more of a first differential filter and a second differential filter of the measurement device.

14. The measurement method according to claim 13 , further comprising:
compensating, via the first differential filter connected to the at least one differential signal input of the measurement device, signal errors caused by one or more of the differential connection interface and the at least one differential signal input, with respect to the at least one differential output signal captured by the measurement device.

15. The measurement method according to claim 13 , wherein the measurement device comprises one or more of an oscilloscope, a logic analyzer, and a spectrum analyzer.

16. The measurement method according to claim 13 , wherein the differential connection interface comprises two cables comprising one of twisted-pair cables and triax cables.

17. The measurement method according to claim 14 , further comprising:
measuring, by the measuring device, a positive signal portion and a negative signal portion of at least one differential input signal at the at least one differential signal input;
determining an individual error with respect to the positive signal portion and the negative signal portion of the at least one differential input signal; and
minimizing the individual error by adjusting at least one filter coefficient of the first differential filter.

18. The measurement method according to claim 14 , further comprising:
measuring, by the measuring device, a common-mode signal portion of at least one differential input signal at the at least one differential signal input;
determining an individual error with respect to the common-mode signal portion of the at least one differential input signal; and
minimizing the individual error by adjusting at least one filter coefficient of the first differential filter.

19. The measurement method according to claim 14 , further comprising:
measuring, by t

Assignees

• Rohde & Schwarz

Inventors

• Peschke Martin

Classifications

• G01R31/31723

  Hardware for routing the test signal within the device under test to the circuits to be tested, e.g. multiplexer for multiple core testing, accessing internal nodes (routing the test signal to or from the device under test G01R31/31926) · CPC title

• G01R19/16557

  Logic probes, i.e. circuits indicating logic state (high, low, O); (modifications of electronic switches or gates for indicating state of switch H03K17/18) · CPC title

• G01R31/31706 Primary

  involving differential digital signals, e.g. testing differential signal circuits, using differential signals for testing · CPC title

• G01R1/06788

  Hand-held or hand-manipulated probes, e.g. for oscilloscopes or for portable test instruments (end pieces terminating in a probe H01R11/18) · CPC title

• G01R23/18

  with provision for recording frequency spectrum · CPC title