There is described a method of determining a phase value for an NFC card emulating device that enables said NFC card emulating device to communicate in phase with an NFC reader device while utilizing active load modulation, wherein the NFC card emulating device comprises a card antenna and the NFC reader device comprises a reader antenna, the method comprising receiving a reader signal from the NFC reader device at the NFC card emulating device through coupling of the card antenna and the reader antenna, the reader signal comprising a subcarrier modulation; estimating a resonance frequency of a system corresponding to the coupled card antenna and reader antenna based on the received communication signal; and determining the phase value based on the estimated resonance frequency and a set of parameters that represents a predetermined reference system. Furthermore, an NFC card emulating device, an NFC system, and a computer program are described.