R3765/67G Series Network Analyzer Operation Manual
7.5 Calibration
7-53
Directivity
A directivity coupler or a directivity bridge used for reflection
measurement detects the reflected signal from the test
device.
However, it not only detects the reflected signal but also a
small amount of the incident signal. The limit between
separating the incident signal and the reflected signal is
referred to as Directivity.
Source Matching
The reflected signal from the test device is reflected again at
the signal source, which causes an incident error to the test
device. This reflection coefficient at the signal source is
referred to as Source Matching.
Load Matching
The signal that passed through the test device is input into the
receiver section. Depending on the reflection coefficient of
the receiver section, the signal is reflected at the receiver
section.
This reflected signal passes through the test device again and
returns to the signal source, causing an error.
This reflection coefficient of the receiver section is referred to
as Load Matching.
Transmission Tracking
This is the measurement frequency transmission
characteristic.
Reflection Tracking
This is the measurement frequency reflection characteristic.
Even while the measurement between TEST PORT1 and TEST PORT2 is being per-
formed, the 3-port full calibration makes a complete error correction for the 3-port net-
work and corrects the error caused by TEST PORT 3.
That is, it corrects the effect caused by the reflection from TEST PORT3.
In the same way, it corrects the error caused by TEST PORT2, while the measurement
between TEST PORT1 and TEST PORT3 is being performed. It also corrects the error
caused by TEST PORT1 while the measurement between TEST PORT2 and TEST
PORT3 is being performed.
However, when the 3-port full calibration is carried out, the measurements are always
performed for all three directions. For example, when the measurement between TEST
PORT1and TEST PORT2 is performed, the measurement between TEST PORT1 and
TEST PORT3 and the measurement between TEST PORT2 and TEST PORT3 are
also carried out.