Here is a picture of the most simple setup
The tinySA at the bottom right is doing the sweeping. Its tracking output from the high connector is connected to the LO port of a mixer.
A generator at 433.8MHz at 1dBm (I used a tinySA at the top right as I do not have a generator) is connected to the RF port and tracking output is coming from the IF port where is goes into a DUT. output of the DUT goes into the low input port of the tinySA.
Instead of a generator at 433.8MHz you may also use a generator with square wave output at 144.6MHz and use the 3rd overtone.
With this setup you can measure the transfer function of a frequency translating device by offsetting the generator.
