Abstract
This paper describes the design and experimental characterization of a battery-less bidirectional 2.45-GHz circuit operating in oscillator mode as a wireless power transmitter or in rectifier mode as an energy harvester, with a measured efficiency greater than 50% in both operating states. The dc voltage harvested in rectifier mode provides the drain bias for the oscillator. The FET-gate self-bias mechanism is exploited in both functionalities, thus eliminating external gate bias. Bi-directionality is based on the time-reversal properties of a transistor oscillator. Energy autonomy is possible at received RF power levels as low as -4 dBm, by means of a bias-assisting feedback loop, consisting of a single matched low-power diode in shunt configuration. A hybrid prototype is demonstrated with the ability to operate as an energy-autonomous power relay node by switching between transmit and receive power modes.
Original language | English |
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Pages (from-to) | 4511-4520 |
Number of pages | 10 |
Journal | IEEE Transactions on Microwave Theory and Techniques |
Volume | 63 |
Issue number | 12 |
DOIs | |
Publication status | Published - Dec 2015 |
Keywords
- Autonomous circuit
- battery-less
- energy harvesting
- microwave oscillator
- rectifier
- wireless power transfer
- EFFICIENCY
- AMPLIFIERS
- RECTIFIER