Amplitude And Phase Tracking; Phase Linearity And Group Delay - Agilent Technologies 8719D User Manual

Amplitude and Phase Tracking

The match between mixers is defined as the absolute difference in amplitude and/or phase
response over a specified frequency range. The tracking between mixers is essentially how well
the devices are matched over a specified interval. This interval may be a frequency interval or
a temperature interval, or a combination of both.
You can make tracking measurements by ratioing the responses of two mixer conversion loss
measurements Then any difference you view in response is due to the mixers and not the
measurement system.
Replace mixer A with the mixer that you want to compare it to. Mixer R should always remain
in place as the reference mixer.
Connections for an Amplitude and

Phase Linearity and Group Delay

Group delay is the rate of change of phase through a device with respect to frequency (d4/dw).
Traditionally, group delay has been used to describe the propagation delay (Tg), and deviation
from linear phase through a linear device. However, this parameter also contains valuable
information about transmission delay and distortion through a non-linear device such as a
mixer or frequency converter. For example, flat group delay corresponds to low modulation
distortion (that is, carrier and sidebands propagate at the same rate).
Phase linearity and group delay are both measurements of the distortion of a transmitted
signal. Both measure the non-linearity of a device's phase response with respect to frequency.
Application and Operation Conoepts
NETWORK ANALYZER
Figure 6-96.
Phase
Tracking Measurement Between Two Mixers
I