scholarly journals A Circularly Polarized Implantable Rectenna for Microwave Wireless Power Transfer

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 121
Author(s):  
Chao Xu ◽  
Yi Fan ◽  
Xiongying Liu
Keyword(s):  
Wireless Power Transfer ◽  
Axial Ratio ◽  
Input Power ◽  
Impedance Bandwidth ◽  
Power Transfer ◽  
Wireless Power ◽  
Circularly Polarized ◽  
Rectangular Slot ◽  
Dc Power ◽  
Implantable Antenna

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.

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
Keyword(s):  
Phased Array ◽  
Wireless Power Transfer ◽  
Axial Ratio ◽  
Input Power ◽  
Power Transfer ◽  
Wireless Power ◽  
Phased Array Antenna ◽  
Power Fluctuation ◽  
Microwave Beam ◽  
Yaw Angle

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%.

scholarly journals Wireless power transfer system rigid to tissue characteristics using metamaterial inspired geometry for biomedical implant applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ramesh K. Pokharel ◽  
Adel Barakat ◽  
Shimaa Alshhawy ◽  
Kuniaki Yoshitomi ◽  
Costas Sarris
Keyword(s):  
Electromagnetic Waves ◽  
Wireless Power Transfer ◽  
Split Ring Resonator ◽  
Input Power ◽  
Power Transfer ◽  
Wireless Power ◽  
Biomedical Implant ◽  
Safety Regulations ◽  
Wireless Power Transfer System ◽  
Tissue Characteristics

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.

A circularly polarized wideband high gain patch antenna for wireless power transfer

2018 ◽  
Vol 60 (3) ◽  
pp. 620-625 ◽  
Author(s):  
C. A. Di Carlo ◽  
L. Di Donato ◽  
G. S. Mauro ◽  
R. La Rosa ◽  
P. Livreri ◽  
...  
Keyword(s):  
Patch Antenna ◽  
Wireless Power Transfer ◽  
High Gain ◽  
Power Transfer ◽  
Wireless Power ◽  
Circularly Polarized

Miniaturized implantable antenna integrated with split resonate rings for wireless power transfer and data telemetry

2017 ◽  
Vol 59 (3) ◽  
pp. 710-714 ◽  
Author(s):  
Huiying Zhang ◽  
Long Li ◽  
Changrong Liu ◽  
Yong-Xin Guo ◽  
Sirao Wu
Keyword(s):  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Implantable Antenna

A compact polarization reconfigurable stacked microstrip antenna for WiMAX application

2020 ◽  
pp. 1-16
Author(s):  
Murari Shaw ◽  
Niranjan Mandal ◽  
Malay Gangopadhyay
Keyword(s):  
Microstrip Antenna ◽  
Impedance Matching ◽  
Axial Ratio ◽  
Dual Band ◽  
Impedance Bandwidth ◽  
Circularly Polarized ◽  
Rectangular Slot ◽  
Substrate Layer ◽  
Linearly Polarized ◽  
Coaxial Probe

Abstract In this paper, a stacked microstrip patch antenna with polarization reconfigurable property has been proposed for worldwide interoperability for microwave access (WiMAX) application. The proposed antenna has two substrate layers: upper and lower layers with two radiating patches connected with the coaxial probe. Without the upper layer the lower square-shaped substrate layer having regular hexagonal radiating patch with probe fed acts as a linear polarized antenna with impedance bandwidth for (S11 ≤ −10 dB) is 370 MHz 10.56% (3.32–3.69 GHz) cover WiMAX (3.4–3.69 GHz) application band. The hexagonal radiating patch is perturbed with an optimum rectangular slot to enhance the impedance bandwidth of the antenna. The lower substrate layer having hexagonal patch with the same probe position is stacked with the upper square-shaped substrate layer with same sized square patch and the upper patch soldered with the coaxial probe. The overall stacked antenna generates a circularly polarized band when the opposite corner of the top square radiating patch of the upper layer is truncated with optimum size. In order to generate another circularly polarized band and to improve the input impedance matching of the stacked antenna, the top radiating patch is perturbed with two slots and a slit. The stacked circularly polarized antenna generates impedance bandwidth of 12.75% (3.23–3.67 GHz) for (S11 ≤ −10 dB) with two circularly polarized bands (3.34–3.37 GHz) and (3.66–3.70 GHz) as per (axial ratio ≤ 3 dB) for WiMAX application. Therefore, the proposed antenna can be used as linearly polarized or dual band circularly polarized according to requirement.

scholarly journals Miniaturized Circularly Polarized Implantable Antenna for ISM-Band Biomedical Devices

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Ke Zhang ◽  
Changrong Liu ◽  
Xueguan Liu ◽  
Huiping Guo ◽  
Xinmi Yang
Keyword(s):  
Patch Antenna ◽  
Axial Ratio ◽  
Microstrip Patch Antenna ◽  
Impedance Bandwidth ◽  
Optimized Design ◽  
Circularly Polarized ◽  
Ism Band ◽  
Microstrip Patch ◽  
Compact Size ◽  
Implantable Antenna

A compact circularly polarized antenna operating at 915 MHz industrial, scientific, and medical (ISM) band for biomedical implantable applications is presented and experimentally measured. The proposed antenna can be miniaturized to a large extent with the compact size of 15 × 15 × 1.27 mm3 by means of loading patches to a ring-shaped microstrip patch antenna. An impedance bandwidth of 10.6% (865–962 MHz) for reflection coefficient less than −10 dB can be obtained. Meanwhile, the simulated 3 dB axial-ratio (AR) bandwidth reaches 14 MHz. Finally, the optimized design was fabricated and tested, and the measured results agree well with simulated results.

scholarly journals Ka-Band Rotman Lens-Based Retrodirective Beamforming System for Wireless Power Transfer

2021 ◽  
Vol 21 (5) ◽  
pp. 391-398
Author(s):  
Hayoung Hong ◽  
Hongsoo Park ◽  
Kanghyeok Lee ◽  
Wonwoo Lee ◽  
Semin Jo ◽  
...  
Keyword(s):  
Time Delay ◽  
Low Cost ◽  
Wireless Power Transfer ◽  
Impedance Bandwidth ◽  
Far Field ◽  
Power Transfer ◽  
Wireless Power ◽  
Ka Band ◽  
True Time Delay ◽  
True Time

A retrodirective beamforming system (BFS) based on a Rotman lens is proposed for far-field wireless power transfer at Ka-band. The true-time-delay property of the Rotman lens allows for a wideband operation covering 28–38 GHz. The designed BFS comprises a Rotman lens with nine beam ports connected to a nine-element linear Vivaldi array. The proposed BFS is implemented using PCB technology for ease of manufacturing and low-cost processing. The simulated and measured results demonstrate that the proposed BFS can generate nine discrete beams over a scan range of ±45° with a wide impedance bandwidth.

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