High Dynamic Range Swept RF/IF Conversion Loss

The HP 8753E’s frequency offset mode enables the testing of high dynamic range frequency converters (mixers), by tuning the analyzer’s high dynamic range receiver above or below its source, by a fixed offset. This capability allows the complete measurement of both pass and reject band mixer characteristics.

‘Ihe analyzer has a 35 dl3 dynamic range limitation on measurements made directly with its R (phaselock) channel. For this reason, the measurement of high dynamic range mixing devices (such as mixers with built in amplification and filtering) with greater than 35 dB dynamic range must be made on either the analyzer’s A or B channel, with a reference mixer providing input to the analyzer’s R channel for phaselock.

This example describes the swept IF conversion loss measurement of a mixer and filter. The output filtering demonstrates the analyzer’s ability to make high dynamic range measurements.

lb avoid the complexity of performing a separate power meter calibration over the RF frequency range while the mixer under test and reference mixer are operating, a broad band power meter calibration is used. The broad band calibration covers the entire range of IF and RF frequencies.

1.Set the following analyzer parameters:

2.Calibrate and zero the power meter.

3.Connect the measurement equipment as shown in Figure 3-10.

Caution ‘Ib prevent connector damage, use an adapter (HP part number 1250-1462) as a connector saver for R CHANNEL IN.

3-12 Making Mixer Measurements

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HP 8753E manual High Dynamic Range Swept RF/IF Conversion Loss