Abstract: The transponder comprises an antenna and a receiver circuit (2) for receiving RF signals, this receiver circuit is implemented with a control mechanism to activate it at least periodically in a listening mode. This receiver circuit is comprises a decoding circuit (4), formed at least by a demodulator (8) and a decoder (10), and a wake-up circuit (14B) to analyze received RF signals in the listening mode and arranged for controlling the activation of the decoding circuit in this listening mode. The wake-up circuit comprises a frequency discriminator (17) and a digital modulation or preamble detector (18) downstream from a field clock generator (28). The wake-up circuit receives as entry an alternating signal branched from the signal chain through the receiver circuit upstream from the demodulator and it activates the decoding circuit only when a modulation or a preamble is detected in a received RF signal by the digital modulation or preamble detector.
Type:
Grant
Filed:
October 11, 2012
Date of Patent:
October 31, 2017
Assignees:
EM Microeclectronic-Marin SA, SMARTRAC TECHNOLOGY Wehnrath GmbH
Inventors:
Michal Prazan, Michal Prokes, Jürgen Fehle, Ulrich Friedrich