Freq Resp Unpreselected Preamp On Functional Test

This test applies to the following models:

Frequency response (aka. Flatness) is defined as the amplitude deviation from the reference amplitude at 50 MHz. The complete analyzer frequency response is measured with several tests.

The model and options of the DUT will determine which tests are run from the list below.

A “buried power sensor” technique is used to characterize the tracking error of a power splitter in order to avoid the relatively large specified tracking error. This technique reduces the measurement uncertainty to verify the frequency-response specification for the 3.6 GHz to 50 GHz range. The buried sensor calibration is valid for four hours.

This test determines the relative frequency response over the frequency range from 3.6 GHz to 50 GHz for the microwave preselector bypass path.

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Required Test Equipment

Test Equipment

Recommended Model Number

Microwave Signal Generator #1

PSG Models
(see equipment list)

Power Meter


Microwave Sensor, Low Power

  • 2 required
  • Options ≤ 526


Microwave Power Splitter

  • Options ≤ 526


Millimeter Power Sensor

  • 2 required
  • Options > 526


Millimeter Power Splitter

  • Options > 526


30 dB Fixed Attenuator


BNC Cable


Coaxial Cable, 2.4 mm


Coaxial Cable, 3.5 mm


Type-N (m) to 3.5 mm (m) adapter


3.5 mm (f) to 3.5 mm (f) adapter
(for 3.5 mm source)


2.4 mm (f) to 3.5 mm (f) adapter
(for 2.4 mm source)


3.5 mm (f) to Type-N (m)
(8485D adapter)


Connection Setups

In the following setups, cables are designated as solid lines and direct connections are designated as dashed lines.

Power Meter Calibration

Splitter Characterization



Freq Resp Unpreselected Preamp On Test Setup