Agilent Technologies 8510C, Operating And Programming Manual

Page: 140 / 391

STIMULUS Functions
Selecting the Number of P oints to Measure
After a F actory Preset, the net w ork analyzer selects 201 p oints p er sw eep. In F requency
Domain mo de, this pro duces 200 equally spaced fr e quency in terv als. T o c hange the n um b er of
p oints:
1.
Press STIMULUS 4
MENU
5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
NUMBER of POINTS . This brings the n um b er of p oints men u
on to the display . The curren t v alue is underlined.
2. Press the appropriate softkey to select 51, 101, 201, 401, or 801 p oints. Sw eep time
increases when y ou c ho ose a higher n um b er of p oints.
Figure 4-34. Number of P oints Menu
Num b er of p oints is alwa ys coupled. Selecting the n um b er of p oints for one c hannel
automatically selects the same n um b er of p oints for the other c hannel.
With broadband sw eeps, resp onses that are narrow with resp ect to the frequency in terv al
may not b e accurately represen ted. F or example, with a 10 GHz sw eep width, the frequency
resolution is:
Numb er of
P oints
F requency Resolution
(10 GHz Span)
51 200 MHz
101 100 MHz
201 50 MHz
401 25 MHz
801 12.5 MHz
This means that with 51 p oints selected, resp onses that are narrow er than 200 MHz are not
represen ted accurately using a 10 GHz sw eep width. Figure 4-35 sho ws the eect of c hanging
the n um b er of p oints from 51 to 401 in suc h a measuremen t.
Measurement Controls 4-61