NFC antenna interface with Microcontroller I/O pin.

Hi,

Our tpms based project need to add NFC circuit to wake up Microcontroller (CC2541). We are using Premo antenna for NFC. https://www.grupopremo.com/upload/cat/TC0502HF.pdf
Output of antenna passes through

this circuit. So far we could able to wake up uC in max.2cm distance. We have to improve this distance. If anyone have any idea or worked on this type of project please give me a solution to improve distance.

Thanks.