Our customer use PN7150. I test the antenna coil parameters. The Rcoil is 16.3ohm,is it a normal value? Besides, the antenna coil locate on the battery, I see the L value change from 1.33uH(remove battery) to 1.2uH(with battery),what kind of influence lead to for the performance and what should we do?
The antenna resistance value is not bad, normally a small value translates into more power to the antenna but taking care not to exceed max transmission current, whilst a bigger antenna impedance is recommended for battery-powered devices; please take a look to the antenna design app note for more information about this.
Regarding the antenna onto the battery, it would be helpful to have a material to isolate them, some recommendations are available in the antenna design videos for NFC.