On the use of the intermodulation communication towards zero power sensor nodes

This paper demonstrates the use of the intermodulation communication principle for long reading range wireless passive sensors. Analytical expressions and measurement results are first reviewed to describe the wireless sensor. Finally the outputs of an ECG (electrocardiography) wireless sensor are given. Results show that reading distances of several tens of meters are achievable with the intermodulation technique, hence setting out this technique as a strong candidate for passive sensor nodes that are the major constituents of wireless sensor networks.