Agilent Technologies E4406A manual Offset A 750.000 kHz Offset B 1.98000 MHz

Making Measurements

Making the Adjacent Channel Power (ACP) Measurement

Data Points - The automatic mode chooses the optimum number of points for the fastest measurement time with acceptable repeatability. The minimum number of points that could be used is determined by the sweep time and the sampling rate. You can increase the length of the measured time record (capture more of the burst) by increasing the number of points, but the measurement will take longer.

Res BW - This key is always grayed out. However, it allows you to see the resolution bandwidth that is derived from the combination of sweep time, data points, and FFT segments.

Num FFT Seg - Allows you to select the number of FFT segments used in making the measurement of the reference channel (carrier). In automatic mode the measurement optimizes the number of FFT segments required for the shortest measurement time. The minimum number of segments required to make a measurement is set by your desired measurement bandwidth. Selecting more than the minimum number of segments will give you more dynamic range for making the measurement, but the measurement will take longer to execute.

•Offset/Limits - Allows you to access the menu to change the following parameters for offset frequency settings and pass/fail tests:

Offset - Allows you to select one of five offsets (A through E). Only one selection at a time (A, B, C, D, or E) is shown on this key label. The remaining softkeys on the Offset/Limits menu then apply to the selected offset.

Offset Freq- Allows you to enter an offset frequency value and toggle the offset frequency function between On and Off. The range is 0.0 Hz to 45.000 MHz. While this key is activated, enter an offset value from the numeric keypad by terminating with one of the frequency unit keys shown. Offsets A and B are defaulted as follows, while others are defaulted to 0.0 Hz:

Offset A 750.000 kHz

Offset B 1.98000 MHz

One offset frequency value corresponding to the Offset key selection is shown on this key label.

Offset Side - Choose Neg (negative) or Pos (positive) to have single-sided offsets relative to the carrier, or Both (the default) to have offset frequency pairs.

Ref BW - Allows you to enter a reference bandwidth ranging from 300 Hz to 20.0000 MHz with the best resolution of 1 Hz. When this parameter is changed, the integration bandwidth Integ BW in the summary data window changes to that value.

126 Chapter 4