send and recieve using microstrip patch antennas

I have a setup using two patch antennas at 10.61 GHz. I'm trying to send and receive using the same set. I'm sending a pulse at 10.61GHz, 30ns duration, which hits a resonator and I'm trying to measure the return pulse after it propogates back through the antennas. I have no problem with the initial pulse, but the return pulse disappears. My math says I should be able to measure the return pulse, but I think there's some sort of interference between the send/receive in the patch antennas.

One of my fellow students thinks its ringing because the patch antennas can't dissipate the send energy fast enough to not interfere with the receive pulse. He suggested a microstrip monopole. Does this sound right? Any ideas how best to make one on PCB?