Single port single connection VNA calibration apparatus

• US 20040054490A1
• Filed: 09/16/2002
• Published: 03/18/2004
• Est. Priority Date: 09/16/2002
• Status: Active Grant

• Current Assignee: Anritsu Co (Anritsu Corporation)
• Original Assignee: Anritsu Co (Anritsu Corporation)
• Inventors: Bradley, Donald Anthony, Hong, Kirby Garyen
• Granted Patent: US 6,917,892 B2
• Time in Patent Office: Days
• US Class Current: 702/107
• CPC Class Codes: G01R 27/04 in circuits having distributed constants , e.g. having very long conductors or involving high frequencies
• 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 and apparatus are used to calibration a Vector Network Analyzer (VNA). The method includes providing a calibration module with a single port, providing within the calibration module a set of reflecting components with known scattering parameters, providing control signals to the calibration module through the single port, providing the known scattering parameters to the VNA through the single port, coupling one of reflecting components to the VNA, measuring scattering parameters, and comparing the measured scattering parameters with the known scattering parameters. The apparatus includes a calibration module and a controller module. In one embodiment, the calibration module includes a set of reflecting components, a memory that stores the characterization data, and a current source which sends characterization data in the form of current pulses to the controller module. The controller module includes a voltage source that generates the control signals used by the calibration module.

Claims

1. An apparatus for use in calibrating a Vector Network Analyzer, the apparatus comprising:

a port;

a set of reflecting components providing a set of known scattering parameters;

a microcontroller operatively coupled to the port and the memory; and

a current source operatively coupled to the microcontroller and the port, wherein the microcontroller is configured for providing the set of known scattering parameters by way of current pulses from the current source.

2. The apparatus of claim 1, further comprising a pulse edge detector operatively coupled to the port and a comparator operatively coupled to the pulse edge detector and the microcontroller, wherein the microcontroller is configured for receiving control signals from the port that are detected by the pulse edge detector and providing the set of known scattering parameters in response to the control signals.

3. The apparatus of claim 2, wherein the control signals comprise at least two voltage levels.

4. The apparatus of claim 1, further comprising a memory operatively coupled to the port and the microcontroller, wherein the memory stores the set of known scattering parameters.

5. The apparatus of claim 4, further comprising a power regulator operatively coupled to the port and the microcontroller and the memory.

6. The apparatus of claim 1, wherein the set of reflection components comprises a short, an open and a low reflection impedance.

7. An apparatus for use in calibrating a Vector Network Analyzer (VNA), the apparatus comprising:

a port;

a set of reflecting components providing a set of known scattering parameters;

a switch having a first end operatively coupled to the port and a second end selectively connectable to individual ones of the set of reflection components, wherein the switch is controlled by a first set of control signals received through the port;

a microcontroller operatively coupled to the port, wherein the microcontroller is controlled by a second set of control signals received through the port; and

a current source operatively coupled to the microcontroller and the port, wherein the current source provides current pulses through the port under direction of the microcontroller.

8. The apparatus of claim 7, further comprising a memory operatively coupled to the port and the microcontroller, wherein the memory stores the set of known scattering parameters.

9. The apparatus of claim 8, further comprising power regulator operatively coupled to the port and the microcontroller and the memory.

10. The apparatus of claim 7, further comprising a voltage sensor operatively coupled to the port and the switch, wherein the voltage sensor is configured for receiving the first set of control signals and for controlling the operation of the switch.

11. The apparatus of claim 7, wherein the set of reflection components comprises a short, an open and a low reflection impedance.

12. The apparatus of claim 7, wherein the first set of control signals comprises at least three voltage levels.

13. The apparatus of claim 7, wherein the second set of control signals comprises at least two voltage levels.

14. An apparatus for use in calibrating a Vector Network Analyzer, the apparatus comprising:

a port;

a processor;

a voltage source operatively coupled to the processor and the port; and

a current to voltage convertor operatively coupled to the port and the processor.

15. The apparatus of claim 14, further comprising a switch having a first end operatively coupled to the processor and a second end selectively connectable to the port.

16. The apparatus of claim 14, further comprising a pulse shaper amplifier and a comparator, wherein the pulse shaper amplifier is operatively coupled to the current to voltage convertor and the comparator, and wherein the comparator is operatively coupled to the pulse shaper amplifier and the processor.

17. An apparatus for use in calibrating a Vector Network Analyzer, the apparatus comprising:

a port;

a processor;

a voltage source operatively coupled to the processor and the port, wherein the voltage source, under direction of the processor, generates control signals to be transmitted through the port; and

a convertor operatively coupled to the processor and the port, wherein the convertor receives current pulses through the port, and wherein the convertor converts the current pulses into voltage levels to be used by the processor.

18. An apparatus for use in calibrating a Vector Network Analyzer (VNA), the VNA having a first port, the apparatus comprising:

a calibration module comprising;

a second port for connecting to the first port;

a set of reflecting components providing a set of known scattering parameters which enable calculation of calibration values used to correct errors introduced by the VNA;

a switch having a first end operatively coupled to the second port and a second end selectively connectable to individual ones of the set of reflection components, wherein the switch is controlled by a first set of control signals received through the second port;

a memory for storing the set of known scattering parameters;

a microcontroller operatively coupled to the memory and the second port, wherein the microcontroller is controlled by a second set of control signals received through the second port; and

a current source operatively coupled to the microcontroller and the second port, wherein the current source provides current pulses through the second port under direction of the microcontroller; and

a controller module comprising;

the first port;

a processor;

a voltage source operatively coupled to the processor and the first port, wherein the voltage source, under direction of the processor, generates the first and second sets of control signals used by the calibration module; and

a convertor operatively coupled to the processor and the first port, wherein the convertor receives the current pulses from the current source of the calibration module, and wherein the convertor converts the current pulses into voltage levels to be used by the processor.

19. The calibration apparatus of claim 18, wherein the set of reflection components comprises a short, an open and a low reflection impedance.

20. The calibration apparatus of claim 18, wherein the microcontroller provides the set of known scattering parameters to the processor by way of the current pulses, and wherein the processor determines the calibration values by comparing the set of known scattering parameters to measured scattering parameters.

21. The calibration apparatus of claim 18, wherein the first set of control signals comprises at least three voltage levels.

22. The calibration apparatus of claim 18, wherein the second set of control signals comprises at least two voltage levels.

23. The calibration apparatus of claim 18, wherein the calibration module is powered by voltage received through the second port.

24. The calibration apparatus of claim 18 wherein the calibration module further comprises a temperature sensor.

25. A method of calibrating a Vector Network Analyzer (VNA), the VNA having a first port, the method comprising the steps of:

providing a calibration module with a second port for connecting to the first port;

providing within the calibration module a set of reflecting components providing known scattering parameters;

providing control signals to the calibration module through the first port;

providing the known scattering parameters to the VNA through the second port;

coupling one of the set of reflecting components to the second port;

measuring scattering parameters after the above coupling step;

comparing the measured scattering parameters with the known scattering parameters; and

determining calibration values which can be utilized to correct errors introduced by the VNA.

26. The method of claim 25, wherein the step of providing control signals to the calibration module through the first port further comprises providing at least three voltage levels.

27. The method of claim 25, wherein the step of providing the known scattering parameters to the VNA through the second port further comprises providing current pulses.

28. The method of claim 25, wherein the step of providing within the calibration module a set of reflecting components comprises providing a short, an open and a low reflection impedance.

29. A method for communicating between a Vector Network Analyzer (VNA) and a calibration apparatus comprising a set of reflecting components providing a set of known scattering parameters, the method comprising the steps of:

providing control signals from the VNA to the calibration apparatus by transmitting at least three voltage levels to the calibration apparatus; and

providing the set of known scattering parameters from the calibration apparatus to the VNA by transmitting current pulses to the VNA.

30. A method for providing control signals to a Vector Network Analyzer calibration apparatus comprising a port and a set of reflecting components providing a set of known scattering parameters, the method comprising the steps of:

providing a processor;

providing a voltage source operatively coupled to the processor and the port; and

generating on the port at least three voltage levels from the voltage source under direction of the processor.

31. A method for providing to a Vector Network Analyzer (VNA) a set of known scattering parameters for a set of reflecting components, the method comprising the steps of:

providing a memory for storing the set of known scattering parameters;

providing a microcontroller operatively coupled to the memory;

providing a current source operatively coupled to the microcontroller; and

transmitting current pulses from the current source to the VNA under direction of the microcontroller.