Wireless Power Transmission to a Buried Sensor in Concrete

Abstract

Abstract-The feasibility of sending wireless power to a buried sensor antenna within concrete was studied. A receive patch rectenna with 75.8% conversion efficiency was designed for operation at 5.7 GHz. The received DC power at the rectenna was measured within dry and wet concrete samples with various cover thicknesses and air-gaps. For the rectenna buried within 30 mm of the concrete, the received DC power was 10.37 mW, which was about 70% of the received DC power in free-space.

A Reconfigurable Stacked Patch Antenna for Wireless Power Transfer and Data Telemetry in Sensors

“…The performance of the rectenna was measured by illuminating it with a four-element microstrip patch antenna array (13.6 dBi gain) described in [22] which was connected to a high-power amplifier (7 W, 5.3-5.9 GHz) and a microwave signal generator. The received voltage at the rectenna was measured using a voltmeter.…”

“…Wireless power transmission in the 5-6 GHz band has been studied before in [15][16][17][18][19][20][21][22][23][24] primarily because of the band being unlicensed and that it allows larger antenna effective apertures resulting in higher antenna gain. Earlier wireless power transmission (at 5.7 GHz) to a buried sensor antenna in concrete was demonstrated in [22].…”

“…Earlier wireless power transmission (at 5.7 GHz) to a buried sensor antenna in concrete was demonstrated in [22]. This was done considering such a scheme to charge the battery of a smart bridge health monitoring sensor.…”

Embedded Antennas in Dry and Saturated Concrete for Application in Wireless Sensors

“…In our research group studies on the characteristics of an embedded microstrip patch antenna at 2.45 GHz were performed [10][11][12]. In [13] the prospects of beaming wireless power to an antenna embedded inside concrete was studied at 5.7 GHz.…”

Optimum Wireless Power Transmission for Sensors Embedded in Concrete

“…While in [50], a 14.5 dBi Yagi antenna transmits 1 W power at 2.5 GHz to a 19 dBi patch antenna 2 m away from it, in order to power the sensors mounted on the surface of Alamosa Canyon Bridge. The typical time for the 0.1 F capacitor to be charged to 3.5 V is 95 s. A stacked patch rectenna with 75.8% DC to AC conversion efficiency was designed for operation at 5.7 GHz for wireless power transmission to a buried sensor in concrete [51]. Dry and wet concrete samples with various cover thicknesses and airgaps are considered, and 10.37 mW power was received at 0.6 m for input power of 7 W.…”