Schwarzbeck CAL CMAD 1614 Calibration Fixture For CMAD 1614

The Schwarzbeck CAL CMAD 1614 calibration fixture is used to calibrate / verify the performance of the common mode absorption device CMAD 1614. The fixture consists of an aluminium base plate with two sideplates, adjustable in height and position and each of them equipped with N-connector and inner conductor fixture. A variety of inner conductors with 4 mm diameter is part of the delivery. The calibration fixture was designed for measurements acc. to CISPR 16-1-4 sections 9.5 and 9.6.

Schwarzbeck CAL CMAD 1614 Application

First of all it is recommended to adjust the height of the inner conductor that it is centered in the CMAD. This can be done by releasing both star knobs and moving the N-connector to the desired position. As soon as the correct height is found, tighten the star knobs and repeat the same for the opposite side. It is advisable to embed the CMAD in the calibration fixture and verify the correct height of the inner conductor, if needed, do a fine adjustment. The height shall not be changed during the TRLcalibration procedure and the following measurement to obtain meaningful results.

Schwarzbeck CAL CMAD 1614 Calibration

The calibration of the CMAD 1614 can be done using the TRL-method. TRL means "Through", "Reflect", "Line" and is usually implemented in modern vector network analyzers. Further information about the application of the TRL-method can be found in the documentation of the network analyzer. The same applies for the data input of the calibration standards. The following table contains the data of the calibration standards to be used by the vector network analyzer. It is worth to notice that the actually measured length of the inner conductors deviates by 14 mm or 28 mm from the tabular values since the inner conductor plugs come with 14 mm length on each side.

Fig. 1: Reflect Port 1 and Reflect Port 2 calibration standards

Fig. 2: Through Calibration Standard

Fig. 3: Line 1 Calibration Standard (For High Frequencies)

Fig. 4: Line 2 Calibration Standard

Fig. 5: CMAD 1614 in Calibration Fixture with Line2

S 11 measured acc. CISPR 16-1-4 Section 9.5

S 11 measured acc. CISPR 16-1-4 Section 9.6