This was a project that I embarked upon simply for the fun of it. In fact, I don’t
really need an S-
With reference to the images on the left, I will try to shed some enlightenment on
the transfer relay and how it is used to turn the VNWA into an S-
The top image is the schematic of the transfer relay itself. As you can see it has
4 connections. Since it is a coaxial relay, these connections are N-
Now referring to the bottom image: TX & RX are the Output and Input ports on the VNWA whilst DUT 1 & 2 are the connectors on the Test Set for connecting the ‘Device Under Test’.
Note that when Position 1 is asserted, RF from port TX is fed through the relay to
DUT 1. RF appearing at DUT 2 is then passed through the relay to port RX. This is
essentially the same as connecting the Device Under Test directly to the VNWA. However
with an S-
When Position 2 is asserted, RF from port TX is now fed to DUT 2 and any RF at DUT 1 is fed to port RX.
Simple and elegant!