Full 3-Port Calibration

• Overview

• Procedure

Other topics about Basic Calibration

Overview

In full 3-port calibration, calibration data are measured by connecting an OPEN standard, a SHORT standard, or a LOAD standard to three desired test ports (or a THRU standard between three ports). This calibration effectively eliminates the directivity error, crosstalk, source match error, load match error, frequency response reflection tracking error, and frequency response transmission tracking error from the test setup in a transmission or reflection test using those ports. As in full 2-port calibration, this calibration method also makes it possible to perform measurements with the highest possible accuracy. There are unique error terms for directivity, source match, and reflection tracking for each stimulus test port (3 × 3 ports = 9). As for isolation, load match, and transmission tracking errors, there are unique terms for each combination between a stimulus port and a response port (3 × 6 combinations = 18). Therefore, in total, 27 error terms are involved in a full 3-port calibration.

• System Z0 should be changed to 1 ohm before calibration when using waveguide calibration kit and measuring waveguide devices.

Procedure

1. Press Channel Next/Channel Prev keys to select the channel for which you want to perform the calibration.

2. Press Cal key.

3. Click Calibrate > 3-Port Cal.

4. Click Select Ports, then select the test ports on which you will perform full 3-port calibration.

Reflection

1. Click Reflection.

2. Connect an OPEN calibration standard to test port x (the connector to which the DUT is to be connected).

3. Click Port x Open to start the calibration measurement (x denotes the test port to which the standard is connected).

   • If you select the calibration kit which has different calibration definitions for each gender, (m) and (f) in the name (label) of the standard displayed in the softkey indicate male (m) and female (f) for the analyzer's connector, respectively.

4. Disconnect the OPEN calibration standard and replace it with a SHORT calibration standard.

5. Click Port x Short to start the calibration measurement (x denotes the test port to which the standard is connected).

6. Disconnect the SHORT calibration standard and replace it with a LOAD standard.

7. Click Port x Load to start the calibration measurement (x denotes the test port to which the standard is connected).

8. Repeat the above procedure for ports y and z.

9. Click Return.

Transmission 

1. Click Transmission.

2. Make a THRU connection between ports x and y (between the connectors to which the DUT is to be connected).

3. Click Port x-y Thru to start the calibration measurement (x and y denote the test ports between which the THRU connection is being made).

4. Repeat above procedure for ports x and z. then for ports y and z.

5. Click Return.

6. If an isolation calibration must be performed using a LOAD standard, follow the procedure below.

7. Click Isolation (Optional).

8. Connect a LOAD standard to each of the three test ports (connectors to which the DUT is to be connected).

9. Click Port x-y Isol to start the calibration measurement (x and y denote the port numbers to which the LOAD standard is connected).

10. Click Return.

11. Click Done to terminate the full 3-port calibration process. Upon pressing this key, calibration coefficients will be calculated and saved. The error correction function will also be automatically enabled.

Connecting standards in full 3-port calibration