Freq Resp High Freq Preamp Off Adjustment

This adjustment is run on Options F13 and F26.

This adjustment is performed in two steps. The first step determines the frequencies which the frequency response will be adjusted (this step is called adaptive flatness). The second step determines the DUT frequency response correction at the frequencies determined in step 1.

The adaptive flatness routine plots out the uncorrected frequency response on the DUT trace. This is done by placing the DUT trace in max hold, then sweeping a source through the frequency band of interest. The trace can be seen as plot of conversion loss versus frequency. The trace data is then extracted from the DUT and processed.

At each correction frequency, the DUT's conversion loss is measured. The loss is normalized to the loss at 50 MHz and this number is placed in the DUT memory. Flatness corrections are generated for each attenuator step. The DUT measurement application uses these stored corrections to make accurate amplitude measurements.

The related performance test for this adjustment is Freq Resp High Freq Preamp Off.

Required Test Equipment

Test Equipment

Recommended Model Number1

Microwave signal generator #1

PSG models
(see main equipment list)

Power meter

N1914A

Microwave power sensor

  • 2 required

N8485A CFT

Power splitter

11667B

Cable, BNC (m) to SMB (f)

8121-2063

Cable, Coaxial 3.5 mm (m) to 3.5 mm (m)

11500E

Adapter, 3.5 mm (m) to 3.5 mm (m)2

83059A

Adapter, 3.5 mm (f) to 3.5 mm (f)

  • For 3.5 mm source

83059B

Adapter, 2.4 mm (f) to 3.5 mm (f)

  • For 2.4 mm source

11901B

Adapter, 3.5 mm (f) to Type-N (m)

  • For the N8485A power sensor

08485-60005
  1. Refer to the main equipment list for a list of alternative models (if available).
  2. The 3.5 mm (m) to 3.5 mm (m) adapter between the power splitter and the DUT is critical in this adjustment. Proper connector care and torqueing practices must be followed in order to insure optimal performance.

Connection Setups

Above 7.5 GHz Adaptive Flatness Setup

 

Power Meter Calibration

 

Splitter Characterization

 

Freq Resp High Freq Preamp Off Adjustment Setup