Atek HP 8753D, User Manual, Page: 462 / 677

T able 7-12. HP 8753D Instrument Specications (6 of 6)
INPUT GENERAL (cont.)
Description Specication Code
GROUP DELA Y CHARA CTERISTICS
Group delay is computed by measuring the phase change within
a specied frequency step (determined by the frequency span
and the number of points per sweep).
Aperture (selectable) (frequency span)/(number of points 01) S-3
Maximum Aperture 20% of frequency span S-3
Range 1/2 2 (1/minimum aperture) S-3
(The maximum delay is limited to measuring no more than 180
of phase change within the minimum aperture .)
A ccuracy (see graph) S-3
The following graph shows group delay accuracy with an
HP 85047A T est Set with 7 mm full 2-port calibration and a 10
Hz IF bandwidth. Insertion loss is assumed to be <2 dB and
electrical length to be ten meters .
Group Delay A ccuracy vs . Aperture
In general, the following formula can be used to determine the accuracy , in seconds , of specic group delay
measurement:
6[0.003 2 Phase A ccuracy (deg)]/Aperture (Hz)
Depending on the aperture and device length, the phase accuracy used is either incremental phase accuracy or
worst case phase accuracy .
frequency span and the number of points per sweep).
Aperture (selectable) (frequency span)/(number of points 01) S-3
Maximum Aperture 20% of frequency span S-3
Range 1/2 2 (1/minimum aperture) S-3
(The maximum delay is limited to measuring no more than 180
of phase change within the minimum aperture .)
A ccuracy (see graph) S-3
7-32 Specications and Measurement Uncertainties