scholarly journals Novel L-Slot Matching Circuit Integrated with Circularly Polarized Rectenna for Wireless Energy Harvesting

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 651 ◽  
Author(s):  
Mohamed M. Mansour ◽  
Haruichi Kanaya
Keyword(s):  
Energy Harvesting ◽  
Radio Frequency ◽  
High Performance ◽  
Low Cost ◽  
Ground Plane ◽  
Single Layer ◽  
Dipole Antenna ◽  
Input Power ◽  
Circularly Polarized ◽  
Compact Size

Radio frequency (RF) power harvesting allows wireless power delivery concurrently to several remote RF devices. This manuscript presents the implementation of a compact, reliable, effective, and flexible energy harvesting (EH) rectenna design. It integrates a simple rectifier circuit with a circularly polarized one-sided slot dipole antenna at 2.45 GHz Industrial, Scientific, Medical (ISM) frequency band for wireless charging operation at low incident power densities, from 1 to 95 μ W/cm 2 . The rectenna structure is printed on a single layer, low cost, commercial FR4 substrate. The integration of the rectifier and antenna produces a low-profile and high performance circularly polarized rectenna. In order to maximize the system efficiency, the matching circuit introduced between the rectifier and antenna is optimized for a minimum number of discrete components and it is constructed using multiple of L-slot defects in the ground plane. For a given input power of − 6 dBm intercepted by the circularly polarized antenna with 3 dBi gain, the peak RF-DC (radio frequency-direct current) conversion efficiency is 59.5 % . The rectenna dimensions are 41 × 35.5 mm 2 . It is demonstrated that the output power from the proposed rectenna is higher than the other published designs with a similar antenna size under the same ambient condition. Thanks to its compact size, the proposed rectenna finds a range of potential applications for wireless energy charging.

scholarly journals Compact Circularly Polarized Multiband Antennas for RFID Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
H. M. El Misilmani ◽  
M. Al-Husseini ◽  
K. Y. Kabalan ◽  
A. El-Hajj
Keyword(s):  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Microstrip Line ◽  
Ground Plane ◽  
Dual Band ◽  
Circularly Polarized ◽  
Multiband Antennas ◽  
Compact Size ◽  
Frequency Identification ◽  
Rfid Applications

This paper presents multiband circularly polarized (CP) antennas for radio frequency identification (RFID). A coax-fed and a microstrip-line-fed antennas having optimized cross-slots in their patches are first designed for dual-band CP operation. The microstrip-line-fed design is then modified, by incorporating a U-shaped slot in its partial ground plane, to achieve additional operation band with a CP characteristic. Simulation and measured results of the presented designs are reported. The measured results are in accordance with the computed ones. The compact size and CP property make these designs suitable for RFID applications.

Sitsen: Passive sitting posture sensing based on wireless devices

2021 ◽  
Vol 17 (7) ◽  
pp. 155014772110248
Author(s):  
Miaoyu Li ◽  
Zhuohan Jiang ◽  
Yutong Liu ◽  
Shuheng Chen ◽  
Marcin Wozniak ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Radio Frequency Identification ◽  
High Performance ◽  
Learning Algorithm ◽  
Low Cost ◽  
Recognition System ◽  
Sitting Posture ◽  
Average Accuracy ◽  
Phase Variations ◽  
Window Approach

Physical health diseases caused by wrong sitting postures are becoming increasingly serious and widespread, especially for sedentary students and workers. Existing video-based approaches and sensor-based approaches can achieve high accuracy, while they have limitations like breaching privacy and relying on specific sensor devices. In this work, we propose Sitsen, a non-contact wireless-based sitting posture recognition system, just using radio frequency signals alone, which neither compromises the privacy nor requires using various specific sensors. We demonstrate that Sitsen can successfully recognize five habitual sitting postures with just one lightweight and low-cost radio frequency identification tag. The intuition is that different postures induce different phase variations. Due to the received phase readings are corrupted by the environmental noise and hardware imperfection, we employ series of signal processing schemes to obtain clean phase readings. Using the sliding window approach to extract effective features of the measured phase sequences and employing an appropriate machine learning algorithm, Sitsen can achieve robust and high performance. Extensive experiments are conducted in an office with 10 volunteers. The result shows that our system can recognize different sitting postures with an average accuracy of 97.02%.

scholarly journals 2D MoS2 Encapsulated Silicon Nanopillar Array with High-Performance Light Trapping Obtained by Direct CVD Process

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 267
Author(s):  
Minyu Bai ◽  
Zhuoman Wang ◽  
Jijie Zhao ◽  
Shuai Wen ◽  
Peiru Zhang ◽  
...  
Keyword(s):  
Silicon Substrate ◽  
High Performance ◽  
Low Cost ◽  
Light Trapping ◽  
Incident Light ◽  
Single Layer ◽  
Chemical Vapor ◽  
Optoelectronic Device ◽  
Planar Silicon ◽  
Shortwave Infrared

Weak absorption remains a vital factor that limits the application of two-dimensional (2D) materials due to the atomic thickness of those materials. In this work, a direct chemical vapor deposition (CVD) process was applied to achieve 2D MoS2 encapsulation onto the silicon nanopillar array substrate (NPAS). Single-layer 2D MoS2 monocrystal sheets were obtained, and the percentage of the encapsulated surface of NPAS was up to 80%. The reflection and transmittance of incident light of our 2D MoS2-encapsulated silicon substrate within visible to shortwave infrared were significantly reduced compared with the counterpart planar silicon substrate, leading to effective light trapping in NPAS. The proposed method provides a method of conformal deposition upon NPAS that combines the advantages of both 2D MoS2 and its substrate. Furthermore, the method is feasible and low-cost, providing a promising process for high-performance optoelectronic device development.

Compact Triple/Quadruple-Band Reconfigurable Monopole Antenna for Wireless Applications

2021 ◽  
pp. 2150277
Author(s):  
Asmaa Zugari ◽  
Wael Abd Ellatif Ali ◽  
Mohammad Ahmad Salamin ◽  
El Mokhtar Hamham
Keyword(s):  
Simple Structure ◽  
Low Cost ◽  
Ground Plane ◽  
Monopole Antenna ◽  
Pin Diode ◽  
Wireless Applications ◽  
Rectangular Patch ◽  
Antenna Performance ◽  
Compact Size ◽  
Multi Band

In this paper, a compact reconfigurable tri-band/quad-band monopole antenna is presented. To achieve the multi-band behavior, two right-angled triangles were etched in a conventional rectangular patch, and a partial ground plane is used. Moreover, the proposed multi-band antenna is printed on a low cost FR4 epoxy with compact dimensions of 0.23[Formula: see text], where [Formula: see text] is calculated at the lowest resonance frequency. To provide frequency agility, a metal strip which acts as PIN diode was embedded in the frame of the modified patch. The tri-band/quad-band antenna performance in terms of reflection coefficient, radiation patterns, peak gain and efficiency was studied. The measured results are consistent with the simulated results for both cases. The simple structure and the compact size of the proposed antenna could make it a good candidate for multi-band wireless applications.

A Dual Frequency RF-DC Rectifier Circuit with a Low Input Power for Radio Frequency Energy Harvesting

2019 ◽  
Vol 28 (03) ◽  
pp. 1950048 ◽  
Author(s):  
Mohamed Mokhlès Mnif ◽  
Hassene Mnif ◽  
Mourad Loulou
Keyword(s):  
Energy Harvesting ◽  
Radio Frequency ◽  
Threshold Voltage ◽  
Output Voltage ◽  
Alternative Energy ◽  
Input Power ◽  
Design System ◽  
Low Input ◽  
Rectifier Circuit ◽  
Radio Frequency Energy

The energy-harvesting radio frequency (RF) can be an attractive alternative energy capable of replacing all or some of the board batteries. The RF waves are present in several high frequencies ([Formula: see text] GHz) and at low power (a few [Formula: see text]W). An energy-harvesting circuit designed must provide 1[Formula: see text]V voltage at minimum that is able to operate an actuator or a sensor. The RF-DC rectifier is the main component of an energy-harvesting circuit. This paper presents a new design RF-DC rectifier circuit using the MOSFET transistors, the capacitors and the inductors. Our proposed circuit is a combination of an Inductor–Capacitor–Inductor–Capacitor (LCLC) serie-parallel resonant tank (SPRT) and rectifier cascade using the Dynamic threshold Voltage Cancellation (DVC) and the technique of the Internal threshold Voltage Cancellation (IVC). Our proposed circuit operates in dual frequencies [Formula: see text][Formula: see text]GHz and [Formula: see text][Formula: see text]GHz with a low input power [Formula: see text][Formula: see text][Formula: see text]W ([Formula: see text][Formula: see text]dbm) and [Formula: see text][Formula: see text][Formula: see text]W ([Formula: see text][Formula: see text]dbm), respectively. This circuit gives a Power Conversion Efficiency (PCE) of 56.9% and an output voltage [Formula: see text][Formula: see text]V for the frequency 2.543[Formula: see text]GHz and a PCE of 62.6% and an output voltage [Formula: see text][Formula: see text]V for the frequency 4[Formula: see text]GHz. The pre-layout simulations were performed using the Advanced Design System (ADS) and the technology used is CMOS 0.18[Formula: see text][Formula: see text]m from TSMC. The simulations were performed on the proposed circuit composed by three stages.

scholarly journals Low Cost Circularly Polarized Antenna for IoT Space Applications

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1564
Author(s):  
Le Huy Trinh ◽  
Nguyen Vu Truong ◽  
Fabien Ferrero
Keyword(s):  
Circular Polarization ◽  
Radiation Pattern ◽  
Insertion Loss ◽  
Low Cost ◽  
Total Efficiency ◽  
Area Network ◽  
Wide Area Network ◽  
Space Applications ◽  
Circularly Polarized ◽  
Compact Size

This work presents the use of a three-element radiating structure for circularly polarized Low-Power Wide Area Network (LP-WAN) communication with space. The proposed structure has a 72 mm × 72 mm × 12 mm compact size with Right-Handed Circular Polarization (RHCP) and a 120∘ wide beamwidth radiation pattern. Printed on low-cost FR4 Epoxy substrate, a feeding network circuit based on Quasi Lumped Quadrature Coupler (QLQC), it achieves a −0.6 dB insertion loss and a very compact size. The final structure has a 69% total efficiency and a 3.14 dBic realized gain.

scholarly journals A Dual-Wideband Double-Layer Magnetoelectric Dipole Antenna with a Modified Horned Reflector for 2G/3G/LTE Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Botao Feng ◽  
Weijun Hong ◽  
Shufang Li ◽  
Wenxing An ◽  
Sixing Yin
Keyword(s):  
Double Layer ◽  
Frequency Band ◽  
Lower Layer ◽  
Low Cost ◽  
Impedance Matching ◽  
Ground Plane ◽  
Dipole Antenna ◽  
Dipole Antennas ◽  
Dipole Structure ◽  
Feeding Structure

A novel dual-wideband double-layer magnetoelectric dipole unidirectional antenna with a modified horned reflector for 2G/3G/LTE applications is proposed. Firstly, a double-layer electric dipole structure is presented to provide a dualwideband, whose folded lower layer mainly serves the lower frequency band while the inclined upper layer works for the upper frequency band. In addition, to reduce the size of the antenna and improve impedance matching, a new feeding structure designed with inverted U-shaped and tapered line is introduced. Finally, a modified horn-shaped reflector, instead of a ground plane, is employed to achieve stable and high gains. The antenna prototype can achieve a bandwidth of 24.4% (790 MHz–1010 MHz) with a stable gain of 7.2 ± 0.6 dBi for the lower band, and a bandwidth of 67.3% (1.38 GHz–2.78 GHz) with a gain of 7.5 ± 0.8 dBi for the upper band covering all the frequency bands for 2G/3G/LTE systems. To the best of our knowledge, it is the first double-layer magnetoelectric dipole antenna proposed. Compared with the existing ME dipole antennas, the proposed antenna, which is completely made of copper, can be easily fabricated at low cost and thus is practicable for 2G/3G/LTE applications.

scholarly journals Wideband circularly polarized cross‐dipole antenna with folded ground plane

2021 ◽  
Vol 15 (5) ◽  
pp. 451-456
Author(s):  
Lei Wang ◽  
Ke‐wen Chen ◽  
Quan Huang ◽  
Wei‐heng Shao ◽  
Wen‐xiao Fang ◽  
...  
Keyword(s):  
Ground Plane ◽  
Dipole Antenna ◽  
Circularly Polarized
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