Simulating a TX/RX pair of antennas in CST

Hi there,
I need help to setup a simulation in CST. I wish to simulate the response of a receiving antenna placed close to a transmitting antenna. Do I need to place to ports, or place one port in the TX antenna and a voltage monitor in the RX antenna?

Hi
I think you need two ports and you can also use two ports or more vector network analyzer in your simulation