Nr.StatusDescriptionFiguresFurther Information
23 project,
Comparative Study Concerning Feasibility and Potential Advantages of Different Circuit Implementation Techniques

Research Partner:
Institute for Microelectronics and Embedded Systems (IMES), Eastern Switzerland University of Applied Sciences, Rapperswil, Switzerland
21 oral presentation,
Harvesting Data Streams for Scattering between Battery-less Transponder and Mobile Telephones

This work studies RF (radio frequency) harvesting of electromagnetic energy from intentionally generated RF sig- nals in the 2.4 GHz ISM band as power supply for a battery-less (back-)scattering transponder. In addition to such a transpon- der, our implementation uses two regular, unmodified mobile telephones, the first one for transmitting WLAN (Wireless Local Area Network) signals and a quasi-continuous Bluetooth (BLE) advertising signal, the second one for receiving the scattered signals from the transponder. The transponder accumulates energy from the incident WLAN and BLE signals for powering a micro-controller, which in turn controls the scattering and modulating of the incident BLE signal. The scattering process applies a 4 MHz frequency translation and frequency shift keying for information transfer such that the scattered signal is detectable by the BLE receiver of the second mobile telephone. The present study implements the WLAN signals as data stream and examines the coexistence of this data stream and the BLE advertising signals as well as the effects of alternative data transfer protocols and different WLAN transmission frequencies. Results show that the User Datagram Protocol (UDP) provides high duty cycle transmissions at an operational range of approx. 2 cm without interfering the scattering process. Thus, the UDP data stream enables an improved wireless power transfer from the transmitting telephone to the battery-less transponder, which enables a significant range extension and encourages further endeavors in this direction.
WPW 2022
Bordeaux, France
IEEE Publication
18 oral presentation,
RF Harvesting at 2.4 GHz for Scattering between Battery-less Transponder and Mobile Telephones

WLAN broadcast signals from the transmitting mobile telephone provide an additional source of energy for our battery-less transponder. Particularly, an Android specific form of WLAN tethering shows the most promising potential for our scattering application, which is based on regular, unmodified mobile telephones.
Delhi, India,
2021 (virtual)
IEEE Publication
15 oral presentation,
Harvesting for Scattering Bluetooth-Signals between Battery-less Transponder and Mobile Telephones

A BLE transmitter of a transmitting mobile telephone provids an quasi-continuous RF signal, which is achieved by using the extended advertizing messages and their periodic retransmissions according to the BLE Standard version 5.0. A specifically designed code sequence generates a quasi-continuous wave signal of approx. 2 ms duration, which provides the basis for the transponder’s scattering process.
Wireless Power Transfer Conference (WPTC),
Seoul, South Korea, 2020 (virtual)
IEEE Publication
13 oral presentation,
Harvesting for Scattering Modulated RF-Signals Receivable by Mobile Telephones

A micro-controller (MCU) of a transponder is operated by using energy of RF harvesting circuit, an external 1 MHz crystal and an internal asynchronous RC oscillator for generating a frequency shift keying modulated subcarrier. The MCU consumes 9.2 mW during active operation.
Wireless Power Week (WPW)
London, UK, 2019
IEEE Publication
10 poster presentation,
Harvesting for Scattering RF-Signals receivable by Mobile Telephones

A battery-less transponder combines RF (radio frequency) harvesting and RF scattering to modulate an incident continuous wave signal such that the scattered signal is receivable by a Bluetooth Low Energy (BLE) receiver of a regular, unmodified mobile telephone.
Wireless Power Transfer Conference (WPTC)
Montreal, Canada, 2018
IEEE Publication
07 poster presentation,
Energy Harvesting in EM Fields

Evaluation of electromagnetic energy and design of a suitable harvesting prototype. The project involved evaluating the potential of energy harvesting in different wireless communication environments, incl. personal cell phones, as well as implementing a harvesting circuit by specifically designing antenna, matching circuit and voltage multiplier. The wirelessly harvested power was sufficient to operate low energy devices such as sensors and microcontrollers (pocket calculator).

Project at FHO-HSR (University of Applied Sciences), Rapperswil, Switzerland
with idp invent ag as project partner
05 Patents and Divisional Application for Sale/License Transponder tag that is operable by a mobile telephone,
portable object, mobile telephone, and corresponding methods

Transponder Tag for receiving wireless signals at a frequency of a local wireless network (ISM radioband), configured to use the energy of these signals for transmitting tag information to a mobile telephone via a short-range RFID connection. This is particularly useful for numerous short distance applications, e.g. for obtaining a quick confirmation that all needed personnel belongings (keys, medical box etc.) are "on board" when leaving home/office.
01 Patents for Sale/License Method of operating an RFID-enabled mobile telephone,
mobile telephone, remote unit and application program product

RFID-enabled Mobile Telephone for quickly and conveniently checking the nearby presence of correspondingly tagged portable objects (keys, medicine box etc.), e.g. before leaving home or office, and a wristwatch for remotely controlling such a telephone