Maximizing RFID Reader Operating Range

I attached a block diagram to better illustrate my design.

Also, after attaching a 12 V power supply directly to the RFID reader, the read range increased dramatically.

Thanks everyone for the help!

Grumpy_Mike, one more quick question. When you say add a capacitor, are you referring to tuning the LC circuit to an optimal operating frequency, or something else that I'm not aware of?