Specifications

RF-IV instruments require calibration every time the instrument is powered on or every time the

frequency setting is changed. This is because ambient temperature, humidity, frequency setting, etc.

have a much greater influence on measurement accuracy than in low frequency impedance mea-

surements. Calibration is performed using open, short, and load reference terminations (a low loss

capacitor termination is also used as necessary) as described in Section 4.7.1. The calibration plane

is at the test port or the tip of test port extension where the calibration reference terminations are

connected (see Figure 4-2.)

Note: The calibration of the RF I-V instruments that should be performed prior to measurements

eliminates impedance measurement errors under the desired measurement conditions. The

RF I-V instruments also require periodic calibration at the recommended intervals for

maintaining their overall operating performance within specifications.

Figure 4-2. Calibration plane of RF-IV instruments

RF impedance/ material analyzer

(a) Open/short/load (+ LLC) calibration at test port

Calibration plane

Open

Short

Load

(b) Open/short/load (+ LLC) calibration at the tip of a port

extension cable

Calibration plane

Open

Short

Load

contact terminals of a test fixture

Calibration plane

Test fixture

Open

(No device)

Short

Load

LLC: Calibration using low loss

capacitor termination

4-2