Antenna-Based Power Generation with Nanoscale Rectifying Elements

“Rectennas” are antennas that can receive radio signals and rectify them to generate electrical power for wireless power transfer. Potential applications for rectennas range from large-scale power transfer applications to small applications such as powering RFID tags or biomedical implants. The usefulness of rectennas is limited by the rectifying element which must convert the electromagnetic (AC) signal to a signal with a non-zero average (DC). In addition standard junction semiconductors that are sometimes used for rectification are relatively inefficient and are unable to extract power from low density signals. A need exists for improved rectifiers to make power generation from electromagnetic signals viable especially in the area of small power transfer applications. UW-Madison researchers have developed a new power generation structure based on the quantum mechanics of nanostructures. A coupled pair of nanopillars serves as the rectifier in a rectenna for power generation. The rectified electromagnetic signal is used to transfer electrons which leads to the buildup of voltage. Embedding these nanoscale rectifiers in broadband antennas creates rectennas with the ability to scavenge energy from the radio frequency to optical frequency range. Rectennas with nanoscale power generation devices have the potential to be used as a universal power source. Applications: 1) Power generation through rectification of electromagnetic signal 2) Large-scale applications such as transfer of power from earth-based stations to satellites 3) Small-scale applications such as RFID tags and biomedical implants like pacemakers


1) Substantially more efficient power generation performance particularly at low power density signals 2) Utilizes common electromagnetic signals (radio waves cell phone communication frequencies) as a power source 3) Consists of silicon that is 10 times less expensive than materials in conventional solar cells

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