Rohde & Schwarz 1145.1010.04/05/06, Руководство по эксплуатации

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R&S
®
ZVA/ZVB/ZVT Trace Menu
1145.1084.12 4.73 E-6
El. Length/Phase Delay
Displays or hides the phase delay (Delay) and the electrical length (EL) of the trace in the selected
evaluation range (Eval Range...) . The parameters are only available for trace formats that contain
phase information, i.e. for the formats Phase, Unwrapped Phase , and the polar diagram formats Polar,
Smith, Inverted Smith . Moreover, the sweep type must be a frequency sweep.
Definition of phase parameters
The phase parameters are obtained from an approximation to the derivative of the phase with respect to
frequency in the selected evaluation range.
•
Delay is the phase delay, which is an approximation to the group delay and calculated as
follows:
,
where f is the width of the evaluation range and is the corresponding phase change. See
also note on transmission and reflection parameters below.
•
EL is the electrical length, which is product of the phase delay times the speed of light in the
vacuum.
If no dispersion occurs the phase delay is equal to the group delay. For more information see
mathematical relations.
If a dispersive connector type (i.e. a waveguide; see Offset Model dialog) is assigned to a test port
related to a particular quantity, then the dispersion effects of the connector are taken into account for
the calculation of the phase delay and the electrical length.
To account for the propagation in both directions, the delay and the electrical length of a
reflection parameter is only half the delay and the electrical length of a transmission parameter.
The formula for PD above is for transmission parameters. See also introduction to section
Channel – Offset.
The phase parameters are available only if the evaluation range contains at least 3 measurement
points.
The phase evaluation can cause misleading results if the evaluation range contains a 360 deg
phase jump. The trace format Unwrapped Phase avoids this behavior.
Remote control: CALCulate<Ch/Tr>:STATistics[:STATe]
CALCulate<Ch/Tr>:STATistics:RESult? ELENgth | PDELay
Compression Point
Displays or hides all results related to the x-dB compression point of the trace, where x is the selected
compression value. To obtain a valid compression point results, a power sweep must be active, the
trace format must be
dB Mag and either an S-parameter or a ratio must be measured.