Firmware for RFID chip AS399x by AMS Microsystem (part 2)
File list:
APP_NOTES
........\AN3992_ RSSI field strength.pdf
........\AS3990-92_AppNote_AntennaMultiplexing_EN_v1.pdf
........\AS3990-92_AppNote_Reflected-power_EN_v1.pdf
........\AS3992_AppNote_EN_v1.pdf