Far-field UHF remotely powered front-end for patient monitoring with wearable antenna

Abstract

The design of a wearable antenna for UHF band at 900 MHz with an integrated front-end for a wireless sensor system targeting remote patient monitoring is presented. A wearable antenna for human body with-7.2 dB gain is demonstrated using five layer torso model. The antenna can deliver 25 µW of power to the rectifier at 4.6 meters distance from the base station emitting PEIRP =4 W. Local power management circuitry consumes a total power of 4 µW while delivering 10 µW of power for the sensors of the wireless sensor system. The system designed with 0.18µm CMOS process demonstrates the performance of the frontend together with 3D electromagnetic simulation results of the wearable antenna.

Advanced Monitoring Systems Based on Battery-Less Asset Tracking Modules Energized through RF Wireless Power Transfer

“…Implementing efficient WPT and RF EH is not a simple task, because even though RF energy offers high pervasiveness and the ability to be directed to out-of-sight locations, its power conversion efficiency (PCE) remains very low. All this has already prompted many researchers to contribute highly enlightening papers on the subject [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67]. This paper contributes to this field of research with an investigation of RF WPT between a power transmitter (reader) and an RF self-powered, battery-less BLE tag within a WSN infrastructure.…”

An RF Wireless Power Transfer system to power battery-free devices for asset tracking

“…For this reason, where possible, such as in low duty-cycle sensors, it is by far preferred to implement battery-free devices, with the evident advantage to render them not-disposable, with virtually unlimited lifetime and more cost efficient [7]. For this reason, batteries are normally avoided and this leads engineers to choose, as power source, primarily RF Wireless Power Transfer (WPT) and where possible even radio-frequency (RF) Energy Harvesting (EH) [8]- [11]. Except for the case of a few centimeters distance between the power source and the supplied device [12], [13], efficient WPT and RF EH is not a simple task [14].…”