transmission line - Radio antenna isolating transformer

I need to isolate galvanically my antenna from my RF transceiver. For this I have been recommended a transformer, I select a 1:1 transformer operating in high frequency range. Is it enough to wire it in between the antenna and the transmitter, or we need to take more considerations. The present antenna impedance is 50E.

I also need recommendation for ferrite core to operate at 900MHz and provide least insertion loss.

Answer

Try CoilCraft - they have this that is suitable for your operating frequency: -

I don't think they can handle much power (1/4 watt say CoilCraft). Insertion loss is 0.7dB which is OK but nothing special. I still believe an air-cored transformer is the best bet.