Agilent Technologies 856290216 Frequency Response Adjustment, Automated Procedure Available

9. Frequency Response Adjustment

9. Frequency Response Adjustment

Assembly Adjusted

Al5 RF assembly

Related Performance Tests

Displayed Average Noise Level

Frequency Response

Description

A signal of the same known amplitude is applied to the spectrum analyzer at several different frequencies. At each frequency, the DAC controlling the flatness compensation amplifiers

is adjusted to place the peak of the displayed signal at the same place on the screen. The preselector is centered at each frequency before setting the DAC value. There are also correction points at 2 MHz and 6 MHz, which are outside the synthesized sweeper frequency range. The DAC values for these two points are set to a fixed offset from the DAC value at 10 MHz. The DAC values are stored in EEROM.

Automated Procedure Available

The frequency response adjustment requires making several measurements at more than

120 different frequencies over the spectrum analyzer frequency range. ‘Ihis manual procedure takes over two hours to complete. However, an automated procedure, with software, is provided by HP. The software can allow the adjustment to be performed in less than

20 minutes. The Automated HP 85623 “Front End Cal” adjustment performs this task, and is described in Chapter 3, “Frequency Response Adjustment Software.”

Adjustment Procedures 2-43