System and method to test and calibrate card-detection using active tag emulation

This specification discloses methods and devices for emulating a tag device that communicates via inductive coupling, such as a NFC (Near Field Communication) tag device. In some embodiments, this specification discloses methods and devices to use this tag device "emulation" for testing, validating, calibrating, and characterizing a reader device. In some embodiments, a tag emulation device can emulate movement of the tag emulation device relative to the reader device by changing configuration parameters of the tag emulation device and by not actually moving the tag emulation device relative to the reader device. In some embodiments, these configuration parameters changes include: changing a Tx (transmitter) voltage, changing a Tx driver impedance, changing a HF (high frequency) attenuator resistance, changing a Tx output modulation, changing a matching network tuning, changing a phase of a Tx signal versus a carrier signal from the reader device, enabling one or two Tx drivers.