Test port input (group delay)1
Table 24. Option 230/235/240/245/260/265/280/285/430/435/440/
445/460/465/480/485
Description
Specification
Supplemental information
Aperture (selectable)
(frequency span)/(number
of points - 1)
Maximum aperture
Minimum delay
25% of frequency span
Limited to measuring no more
than 180 °C of phase change
within the minimum aperture.
Accuracy
See graph below, typical
The following graph shows group delay accuracy with type-N connectors, full 2-port
calibration and a 10 Hz IF bandwidth.
Calibration kit (85032F). Insertion loss is assumed to be < 2 dB.
100
10
1
0.1
0.01
0.001
0.01
0.1
1
10
100
Aperture (MHz)
In general, the following formula can be used to determine the accuracy, in seconds, of a
specific group delay measurement:
phase accuracy (degrees) / [360 x aperture (Hz)]
1. Group delay is computed by measuring the phase change within a specified step (determined by
the frequency span and the number of points per sweep).
25
HP [ HEWLETT-PACKARD ]
