It's not easy. You need to tune the coil to 13.56MHz using a filter. I'd suggest following the eval board schematic and layout as much as possible. However, if you are using a different coil than what is on the PCB, then the values of the caps will need to be changed. The way I tuned the PCB antenna was that I used adjustable caps. I simply moved the capacitor values around until I got a good read. Then I measured the capacitance off of adjustables and used those values. Also, the module has two pins for the antenna (pins 24 and 26), which connect to each end of the coil, and two ground connections that just need to be connected to the main ground.
↧
