scholarly journals Wireless Power Transfer to a Microaerial Vehicle with a Microwave Active Phased Array

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Shotaro Nako ◽  
Kenta Okuda ◽  
Kengo Miyashiro ◽  
Kimiya Komurasaki ◽  
Hiroyuki Koizumi

A wireless power transfer system using a microwave active phased array was developed. In the system, power is transferred to a circling microaerial vehicle (MAV) by a microwave beam of 5.8 GHz, which is formed and directed to the MAV using an active phased array antenna. The MAV is expected to support observation of areas that humans cannot reach. The power beam is formed by the phased array with eight antenna elements. Input power is about 5.6 W. The peak power density at 1,500 mm altitude was 2.63 mW/cm2. The power is sent to a circling MAV. Therefore, the transfer beam should be polarized circularly to achieve a constant power supply independent of its yaw angle. To minimize the polarization loss, a sequentially routed antenna (SRA) was applied to the transmitter antenna. Results show that the axial ratio of 0.440 dB was accomplished and that power fluctuation was kept below 1%.

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 121
Author(s):  
Chao Xu ◽  
Yi Fan ◽  
Xiongying Liu

A circularly polarized implantable antenna integrated with a voltage-doubled rectifier (abbr., rectenna) is investigated for microwave wireless power transfer in the industrial, scientific, and medical (ISM) band of 2.4–2.48 GHz. The proposed antenna is miniaturized with the dimensions of 7.5 mm × 7.5 mm × 1.27 mm by etching four C-shaped open slots on the patch. A rectangular slot truncated diagonally is cut to improve the circular polarization performance of the antenna. The simulated impedance bandwidth in a three-layer phantom is 30.4% (1.9–2.58 GHz) with |S11| below −10 dB, and the 3-dB axial-ratio bandwidth is 16.9% (2.17–2.57 GHz). Furthermore, a voltage-doubled rectifier circuit that converts RF power to DC power is designed on the back of the antenna. The simulated RF-to-DC conversion efficiency can be up to 45% at the input power of 0 dBm. The proposed rectenna was fabricated and measured in fresh pork to verify the simulated results and evaluate the performance of wireless power transfer.


2020 ◽  
Vol 35 (9) ◽  
pp. 1073-1079
Author(s):  
Mohammed Aseeri ◽  
Waleed Alomar ◽  
Hamad Alotaibi ◽  
Abdulrahman Aljurbua

Retrodirectivity have several important applications in communication and in wireless power transfer. In this paper, frequency sensitive retrodirective transceiver is proposed. It receives a signal and infers its direction from its frequency spectrum, then it can transmit a new signal back to the same or other direction at the designer wish. To determine the direction of the coming signal, a 0.85-1.15GHz frequency scanning phased array antenna is used so that the received signal would have a distorted spectrum with the maximum amplitude frequency component linked to the direction of the signal. Based on the frequency scanning, the retrodirectivity system can be used for wireless power transfer or for reactive jamming. Special circuit is designed to receive the signal with strongest power and to isolate the frequency component with maximum amplitude. Phase-locked loop (PLL) circuit is used to link such frequency to specific phase shift that is introduced to the transmitter array antenna to send a new signal to the same direction of the received signal. ADS simulation is performed to demonstrate the performance of each block.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ramesh K. Pokharel ◽  
Adel Barakat ◽  
Shimaa Alshhawy ◽  
Kuniaki Yoshitomi ◽  
Costas Sarris

AbstractConventional resonant inductive coupling wireless power transfer (WPT) systems encounter performance degradation while energizing biomedical implants. This degradation results from the dielectric and conductive characteristics of the tissue, which cause increased radiation and conduction losses, respectively. Moreover, the proximity of a resonator to the high permittivity tissue causes a change in its operating frequency if misalignment occurs. In this report, we propose a metamaterial inspired geometry with near-zero permeability property to overcome these mentioned problems. This metamaterial inspired geometry is stacked split ring resonator metamaterial fed by a driving inductive loop and acts as a WPT transmitter for an in-tissue implanted WPT receiver. The presented demonstrations have confirmed that the proposed metamaterial inspired WPT system outperforms the conventional one. Also, the resonance frequency of the proposed metamaterial inspired TX is negligibly affected by the tissue characteristics, which is of great interest from the design and operation prospects. Furthermore, the proposed WPT system can be used with more than twice the input power of the conventional one while complying with the safety regulations of electromagnetic waves exposure.


Author(s):  
Victor Farm-Guoo Tseng ◽  
Sarah S. Bedair ◽  
Nathan Lazarus

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