Unknown Thru Calibration

NA Mode offers a 'Full 2-port' calibration. When measuring a non-insertable DUT, an 'Unknown Thru' Cal is performed automatically. This Cal type is also known as Short-Open-Load-Reciprocal Thru (SOLR). You are prompted to 'Connect port 1 to port 2 with optional adapter'. This means that ANY cable / adapters can be used to connect port 1 to port 2.

Unknown Thru Cal is the preferred (and ONLY) THRU method for calibrating the FieldFox to measure a non-insertable device. Learn what insertable and non-insertable device means.

• Very easy to perform.

• Better accuracy than using a Defined Thru from a Cal Kit as it does not rely on existing standard definitions that may no longer be accurate.

• Causes minimal cable movement if the THRU standard has the same footprint as the DUT. In fact, the DUT can often BE the THRU standard.

About the Unknown Thru Process

FieldFox guides you through the process.

1. Perform 1-port cal on port 1.

2. Perform 1-port cal on port 2.

3. Connect Unknown Thru between ports 1 and 2.

4. Measure Unknown Thru.

The Unknown Thru Standard

• Can have up to about 40 dB of loss and long electrical length.

• Must be reciprocal: S21=S12.

• Can be the DUT if it meets these conditions.

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