User`s guide

3-4 Chapter3
Theory of Operation and Troubleshooting
Theory of Operation
LED Front Panel
The front panel LEDs indicate whether the test port is the incident port,
the receiver port, or the inactive port. The test port LED that is the
brightest is the incident port. The test port LED that is dim is the
receiver port. The test port LED that is off is the inactive port where no
signal separation is taking place. When performing a forward
transmission or reflection measurement, the analyzer’s source power is
directed to Port 1. This is indicated by a bright LED. If the Port 2 LED is
dim, this is the receiver port. The Port 3 LED is off in this condition and
is inactive. Only two LEDs are on at any given time.
Transfer Switch S0
The A3 source output is directed via a low-loss solid-state switch. With
this switch, all four S-parameters can be measured continuously. In
addition, the transfer switch provides termination for the receiver test
port in order to minimize the crosstalk between source and receiver
sampler.
Port 2 and 3 Source Switch S1
S1 is the source separator for Port 2 and Port 3. In addition, the Port 2
and Port 3 source switch provides termination for the inactive test port
to minimize the crosstalk to either source and receiver sampler and
provide a load match to the device under test.
A Sampler Receiver Switch S2
Provides reflected or transmitted measured signals from Port 1 or Port 2
to the A channel sampler.
B Sampler Receiver Switch S3
Provides reflected or transmitted measured signals from Port 2 or Port 3
to the B channel sampler.
Port 2 Receiver Switch S4
Provides reflected or transmitted signals from Port 2 to be directed to
either A or B channel samplers.