To Decrease The Frequency Span - Agilent Technologies 8753ET User Manual

Optimizing Measurement Results
Increasing Sweep Speed
Sweep Speed-Related Errors
IF delay occurs during swept measurements when the signal from the analyzer source is
delayed in reaching the analyzer receiver because of an electrically long device. The
receiver has a narrow IF band pass filter that tracks the receiver frequency because the
receiver is sweeping. The delayed signal will be attenuated because the center of the
internal IF filter has moved.
For most measurements, swept list mode will be the optimum choice. If there is any doubt
about the effect of IF delay, perform the following test:
1. Set up the measurement using the swept list mode, as in the previous procedure.
2. Make the measurement and save the data trace to memory:
DATA → MEMORY DISPLAY: DATA
Display
3. Then switch to stepped list mode:
SWEEP TYPE MENU
Sweep Setup
• If there is no difference between the measurements in either list mode, then use the
swept list mode.
• If the memory trace indicates that there is more attenuation in swept list mode, it
may be due to IF delay. You can usually remedy this problem by increasing the sweep
time.
NOTE IF bandwidths of 30 to 10 Hz cause the sweep (or that segment of the sweep)
to always be stepped, thus eliminating IF delay.

To Decrease the Frequency Span

The hardware of the network analyzer sweeps the frequency range in separate bands,
where switching from band to band takes time. Modify the frequency span to eliminate as
many band switches as possible while maintaining measurement integrity. Refer to the
following table to identify the analyzer's band switch points:
Table 5-3 Band Switch Points
Band Frequency Span
0 0.01 MHz to 0.3 MHz
1 0.3 MHz to 3.3 MHz
2 3.3 MHz to 16 MHz
3 16 MHz to 31 MHz
4 31 MHz to 61 MHz
5 61 MHz to 121 MHz
6 121 MHz to 178 MHz
5-10
and
MEMORY
EDIT LIST LIST TYPE: [STEPPED]
Band Frequency Span
7 178 MHz to 296 MHz
8 296 MHz to 536 MHz
9 536 MHz to 893 MHz
10 893 MHz to 1.607 GHz
11 1.607 GHz to 3 GHz
12 (Option 006) 3 GHz to 4.95 GHz
13 (Option 006) 4.95 GHz to 6 GHz
DONE