TMS3705: expected RF range

Hello, this is my first post here.

I'm working on an RFID solution using the TMS3705 base station in conjunction with 32mm glass transponders (TI TRPGR30ATGB).

Using the reference circuit from the TMS3705 data sheet I have a working solution that allows me to reliably read tags at a distance of about 10cm. While this is acceptable, it would be very useful to increase the RF range to at least 50cm (the tags themselves have a range specification of up to 110cm according to the datasheet).

I have looked at the range extender solution using the UCC27424 amplifier to drive the antenna. However the purpose of that seems to be to increase the cable distance between the base station and the antenna, rather than increase the RF range. Experiments seem to bear this out in that it still works, but the RF range is essentially the same.

So, my question is: what range can reasonably be expected with these devices and what can be done to maximise it?
Is it purely down to antenna design, or would additional circuitry be required (e.g. a masthead amplifier or different base station hardware)?

Thanks in advance,
Marty