A Compact 3-D Harmonic Repeater for Passive Wireless Sensing and Remote Channel Calibration

Suitable for environments with low light, temperature variation, and vibrationLong distance transmission from a completely passive deviceLow device and installation costDesign provides for flexibility and mobilityHas omni-directional interrogation capability

powering wireless devices

In the last decade, environmental, industrial, and military monitoring applications have motivated an enormous amount of research activity related to wireless sensing. Some applications, such as structural health monitoring would benefit from sensing that is deeply embedded in the environment for extended periods of time. For these applications, it is desirable that the sensing devices have long operational life-cycles, and compact geometries for ease of deployment. Energy consumption is an additional important consideration for embedded wireless sensing applications. The sensors can often be employed in difficult to reach locations with little access to ambient energy. Therefore, it would be useful to have a passive device that also provides sufficient wireless transmission range.Radio frequency (RF) interrogation is a typical approach for providing power to wireless devices. Both passive radio frequency identification (RFID) and surface acoustic wave (SAW)-based devices operate on this premise but are constrained to short-range implementations, typically a few feet. USF inventors have invented a compact 3-D harmonic repeater for passive wireless sensing and remote channel calibration that satisfies the aforementioned design requirements. This approach provides for remote calibration of passive sensors using orthogonal polarization of the interrogation signal for narrow band, wireless sensing applications. The invention far exceeds currently available designs, in terms of conversion gain, communication range, and occupied electrical volume.

USA