Atec Agilent-N5230A - Manual (Page 22)

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Table 9. Test port input (group delay)
Description Specification Supplemental information (typ.)
Aperture (selectable) (frequency span)/(number of points –1)
Maximum aperture 20% of frequency span
Range 0.5 x (1/minimum aperture)
Maximum delay Limited to measuring no more than 180° of
phase change within the minimum aperture
Accuracy See graph below. Char.
The following graph shows characteristic group delay accuracy with 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.
For any S
ij
group delay measurement, S
ii
= 0, S
ij
= 0, S
kl
= 0 for all kl ≠ ij
In general, the following formula can be used to determine the accuracy, in seconds, of specific group delay
measurement:
±Phase Accuracy (deg)/[360° Aperture (Hz)]
Depending on the aperture and device length, the phase accuracy used is either incremental phase accuracy or
worst case phase accuracy.
Group delay (typical)
0.001
0.01
0.1
1
10
100
Accuracy (nsec)
N5230A Option 140/145/146/240/245/246 with 85052B
Frequency = 1 GHz
S11 = 0; S21 = 1; S12 = 0; S22 = 0
IF bandwidth = 10 Hz; Average factor = 1
Cal power = -5 dBm; Meas power = -5 dBm; Electrical length = 10 m
0.01 0.1 1 10 100
Aperture (MHz)