Method of characterizing a device under test

• US 6,230,106 B1
• Filed: 10/13/1999
• Issued: 05/08/2001
• Est. Priority Date: 10/13/1999
• Status: Expired due to Fees

• Current Assignee: Xcerra Corporation (COHU Incorporated)
• Original Assignee: Modulation Instruments, Inc. (COHU Incorporated)
• Inventors: Metzger, Donald William
• Primary Examiner(s): ASSOUAD, PATRICK J
• Application Number:
  US09/419,012
• Time in Patent Office: 573 Days
• Field of Search: 702/85, 702/104, 702/107, 324/601, 324/602, 324/603, 324/629, 324/649
• US Class Current: 702/85
• CPC Class Codes: G01R 27/28 Measuring attenuation, gain, phase shift or derived characteristics of electric four pole networks, i.e. two-port networks; Measuring transient response in line transmission systems H04B3/46
• CPC Class Codes: G01R 31/2822 of microwave or radiofrequency circuits of attenuation, gain, e.g. using network analyzers G01R27/28
• CPC Class Codes: G01R 35/005 Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references G01R33/0035, G01R35/002 take precedence

Abstract

A method of characterizing a device under test involves the steps of first inserting a calibration standard in a test setup. Second, a calibration signal is applied to the test setup. Third, a number of vector error correction coefficients are determined. Fourth, the device under test is inserted in the test setup. Fifth, a non-sinusoidal signal is applied to the test setup. Sixth, a response to the non-sinusoidal signal is measured.

Claims

1. A method of characterizing a device under test, comprising the steps of:

(a) inserting a calibration standard in a test setup;

(b) applying a calibration signal to the test setup;

(c) determining a plurality of vector error correction coefficients;

(d) inserting the device under test in the test setup;

(e) applying a non-sinusoidal signal to the test setup; and

(f) measuring a response to the non-sinusoidal signal.

2. The method of claim 1, further including the step of:

(g) determining a vector error corrected transfer function of the device under test.

3. The method of claim 1, further including the step of:

(g) determining a vector error corrected output of the device under test.

4. The method of claim 1, wherein step (b) further includes the step of:

(b1) applying a sinusoidal signal to the test setup.

5. The method of claim 1, wherein step (b) further includes the step of:

(b1) applying a non-sinusoidal signal to the test setup.

6. The method of claim 1, wherein step (b) further includes the step of:

(b1) applying a plurality of sinusoidal signals one at a time.

7. The method of claim 1, further including the step of:

(g) determining a frequency domain representation of the response to form a spectral output.

8. The method of claim 1, further including the step of:

(h) applying the plurality of vector error correction coefficients to the spectral output to form a vector error corrected spectral output.

9. The method of claim 8, further including the steps of:

(i) converting the vector error corrected spectral output into a vector error corrected time domain output.

10. A computer readable storage medium containing computer readable instructions that when executing by a computer performs the following steps:

(a) requesting a user insert a calibration standard in a test setup;

(b) applying a calibration signal to the test setup;

(c) determining a plurality of vector error correction coefficients;

(d) requesting the user insert a device under test in the test setup;

(e) applying a non-sinusoidal signal to the test setup; and

(f) measuring a response to the non-sinusoidal signal.

11. The computer readable storage medium of claim 10, wherein step (b) further includes applying a plurality of calibration signals.

12. The computer readable storage medium of claim 11, wherein step (c) further includes the steps of:

(c1) calculating a plurality of vector error correction coefficient sets;

(c2) forming a vector error correction model of the test setup.

13. The computer readable storage medium of claim 10, further including the steps of:

(g) applying a windowing function to the response to form a window response;

(h) calculating a frequency domain representation of the window response to form a window frequency domain output;

(i) applying the plurality of vector error correction coefficients to the window frequency domain output to form a window vector error corrected frequency domain output.

14. The computer readable storage medium of claim 10, further including the steps of:

(g) calculating a frequency domain representation of the response to form a frequency domain output;

(h) applying the plurality of vector error correction coefficients to the frequency domain output to form a vector error corrected frequency domain output;

(i) calculating a time domain representation of the vector error corrected frequency domain output to form a vector error corrected time domain output.

15. A method of characterizing a device under test, comprising the steps of:

(a) inserting the device under test in a test setup;

(b) applying a modulated signal to the test setup; and

(c) measuring a response to the modulated signal.

16. The method of claim 15, wherein step (a) further includes the step of:

(a1) inserting a calibration standard in a test setup;

(a2) determining a vector error correction model for the test setup.

17. The method of claim 16, wherein step (a2) includes the step of applying a calibration signal to the test setup.

18. The method of claim 16, further including the steps of:

(d) converting the response to a frequency domain to form a frequency domain output;

(e) applying the vector error correction model to the frequency domain output to form a vector error corrected frequency domain output.

19. The method of claim 18, further including the steps of:

(f) determining a time domain representation of the vector error corrected frequency domain output.

20. The method of claim 18, wherein step (d) further includes the steps of:

(d1) digitizing the response to form a digitized output;

(d2) windowing the digitized output to form a window output;

(d3) converting the window output to a frequency domain representation to form a frequency output;

(d4) applying the vector error correction model to the frequency output to form a vector error corrected frequency output.