Increase the range of an NFC antenna on an already existing PCB. Current range is [url removed, login to view], want to increase to 4cm or more. The antenna trace on PCB can't be changed because of space limitation. NFC is driven using a NXP MFRC630 IC. The range can only be increased by tuning the antenna circuit (see attached schematics) and/or optimizing the MFCR630 registers. A PCB will be provided for testing. Antenna trace can be accessed by removing resistors R10 and R11.