Wideband differential impedance matching

Hello there.

I have a question about impedance matching when you have a balanced connection.
I have this network that has two balanced outputs that have 100 ohms each.
I want to bring it to 50 ohm unbalanced impedance.
The frequency of operation is between 200 and 400 MHz.
Now, the most logical answer right away would be: use a transformer or a balun transformer using coax cables.
The only problem here is that I need to see the response further into high frequency.
I need to know if I can see the response as high as 5 Ghz as least.

Not sure if this is possible using transformers or TLTs.

Can anyone advise if there is such a thing as a wideband transformation method from unbalanced to balanced impedance?

If not, what are my options? If there are any that is.

Thank you very much for reading my message.