bidirectional RF amplifier

hello there! i've been working in an RFID reader whose read range or the effective distance of the RFID tag is from the reader is only 3cm and i need it to have a read range of 14 inches. does anyone know how i can achieve this and how to design a power amplifier in bidirectional mode and is operating at 13.56MHz.

I really need and woul appreciate all the help that i can get. THANK YOU IN ADVANCE!

There are two factors. I am assuming that this system of yours is the type where the tag changes its impedance which is reflected by mutual inductance to the reader.

Factor one is that you have to have a large enough field from the reader to power the tag. This is a function of coil area and input power.

Factor two is the returned effect. This is a function of the mutual inductance between the two coils and the noise level at the reader.

This gives you many things to optimize.