differential current source

How to creat a differential current source? If using balun, how to build the topology?
By the way, I am building a fully differential TIA test bench? Thank you in advance if anyone with experience can provide any suggestion.

You may want to tell a few key parameters to make understandable what you are trying to achieve (Frequency range, current range,
intended minimum output impedance). Generally, you'll find many possible topologies in existing electronic designs.

Yeah, I agree, post your requirements. I would not consider a Balun as a current source...as soon as the H field collapses, you would have nothing for current output.