[HELP] building one UHF band combiner

Hi everyone,

My buyer want to help to build the following jig,which requirement listed as below.
Could somebody give me some suggestion?

Thanks very much


test rig built to do a particular experiment.
The details of the design are:
Two female COAX inputs
One female COAX output

Both inputs should have adjustable gain so that the incoming signals can be
reduced during tests.
The frequency response should be at least within the UHF frequency band.

The two inputs should be reverse wired from each other. That means that
INPUT-1 = +/- and INPUT-2 = -/+
So if I feed two identical signals in the input, and the gain is set to be
the same on both inputs, the output should be 0 signal.

What is exactly the frequency range for this circuit?

bye

UHF: 470-862 MHz,
if it could cover 47-862 Mhz, it will be better

for the requirement you can use a ferrite transmission line power combiner because it can give wide bandwidth