Leijun Xu

ORCID: 0000-0003-2885-6102
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About
Contact & Profiles
Research Areas
  • Microwave Engineering and Waveguides
  • Radio Frequency Integrated Circuit Design
  • Energy Harvesting in Wireless Networks
  • Antenna Design and Analysis
  • Terahertz technology and applications
  • Advanced Chemical Sensor Technologies
  • Spectroscopy and Chemometric Analyses
  • Millimeter-Wave Propagation and Modeling
  • Photonic and Optical Devices
  • Superconducting and THz Device Technology
  • Advanced Power Amplifier Design
  • Electromagnetic Compatibility and Noise Suppression
  • Advanced MIMO Systems Optimization
  • Innovative Energy Harvesting Technologies
  • Wireless Power Transfer Systems
  • Advancements in PLL and VCO Technologies
  • Antenna Design and Optimization
  • Advanced Antenna and Metasurface Technologies
  • Acoustic Wave Resonator Technologies
  • Identification and Quantification in Food
  • Mycotoxins in Agriculture and Food
  • stochastic dynamics and bifurcation
  • Metamaterials and Metasurfaces Applications
  • Neural dynamics and brain function
  • Semiconductor Quantum Structures and Devices

Shanghai Institute of Optics and Fine Mechanics
2023-2024

Jiangsu University
2015-2024

University of Chinese Academy of Sciences
2023-2024

Chinese Academy of Sciences
2023-2024

Southeast University
2008-2021

The Aerospace Corporation
2018

State Key Laboratory of Millimeter Waves
2015

Jiangsu Provincial Meteorological Bureau
2014

Jiangsu University of Technology
2001

Abstract Uncooled broadband spectrum detection, spanning from visible to mid‐wave‐infrared regions, offers immense potential for applications in environmental monitoring, optical telecommunications, and radar systems. While leveraging proven technologies, conventional photodetectors are encumbered by high dark currents the necessity cryogenic cooling. Correspondingly, innovative low‐dimensional materials like black phosphorus manifest weak photoresponse instability. Here, tantalum nickel...

10.1002/adfm.202305380 article EN Advanced Functional Materials 2023-09-22

This study proposes a novel qualitative and quantitative analysis method for wheat mildew degree aflatoxin B1 (AFB1) by microwave detection technology combined with multi-task learning strategy. The team developed miniaturized device double heterodyne mixing structure, used this to obtain the transmission indexes (amplitude phase) of moldy samples. A model based on convolutional neural network (CNN) structure was designed realize self-learning calibration indexes, complete classification...

10.1016/j.lwt.2023.115047 article EN cc-by-nc-nd LWT 2023-07-01

In this paper, the RF energy harvesting system and RF-based wireless power transfer are proposed designed for battery-less self-sustaining application. For harvesting, antenna array improves received effectively also can harvest in multi-frequency bands. transfer, helical realizes design miniaturization. Subsequently, T shape LC matching network between rectifying circuit to obtain more transmission. The measured results show that Wi-Fi rectifier 433 MHz offer a maximum conversion efficiency...

10.1002/mmce.21658 article EN International Journal of RF and Microwave Computer-Aided Engineering 2018-12-19

In this article, a new 2 × circular microstrip antenna array with air dielectric layer for ambient RF energy harvesting has been proposed. Two pairs of arc-shaped slots located close to the boundary patch have designed achieving dual-band response and extending frequency bandwidth. The bandwidth from 1.85 1.93 GHz 2.0 2.1 which can cover GSM-1800 UMTS-2100 bands. At 1.89 2.05 GHz, measured gain is 5.3 6.6 dBi, respectively, high 3.8-9.3 dBi achieved over whole band. Also, broadband rectifier...

10.1002/mmce.21636 article EN International Journal of RF and Microwave Computer-Aided Engineering 2019-01-01

For the miniaturisation of terahertz detector with on‐chip antenna, slotted patch antennas in different shape are studied. Through analysing and comparing rectangle, circular diamond shape, without slot, double arc slots diagonal proposed for antenna respectively, which can increase current path to reduce size effectively. The optimised radius is 130 μm 207.2 μm, whose reduced about 12 40%, respectively. Fabricated Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 standard complementary...

10.1049/iet-map.2017.0833 article EN IET Microwaves Antennas & Propagation 2018-02-08

Abstract Different on‐chip antennas in Complementary Metal‐Oxide‐Semiconductor (CMOS) technology for THz detector and source are proposed. Firstly, the size of these is estimated with an equivalent CMOS substrate model. Finally, through electromagnetic simulation, structure optimised slotted antenna to realise multi‐band detection, miniaturised source. For detector, a dual‐ring circular diamond structures designed. At frequency 300, 600, 800 GHz, gain ring 5.7, 7.2, 7.2 dBi, respectively....

10.1049/mia2.12361 article EN cc-by-nc-nd IET Microwaves Antennas & Propagation 2023-04-24

Abstract The switching speed of light polarization plays a crucial role in determining the upper‐limit bandwidth applications like optical communications and laser microscopy. However, conventional elements based on macroscopic anisotropic crystals birefringent chalcogenide glasses are either static or restricted by low time about hundreds picoseconds. Here, femtosecond‐scale all‐optical controlling method is proposed through engineering excited hot electrons graphene‐loaded metasurface....

10.1002/lpor.202300643 article EN Laser & Photonics Review 2023-11-20

The analysis and design of a millimeter-wave passive balun on silicon substrate with small size good balance is presented. reason for the imbalance analyzed novel method using two grounded T bars beneath coupled lines to tune proposed. was fabricated in 65 nm CMOS process, by broadside separation, length reduced, resulting only 0.01 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . In 57-67 GHz band, measured amplitude less than 0.5...

10.1109/lmwc.2013.2288270 article EN IEEE Microwave and Wireless Components Letters 2013-11-19

10.1007/s10762-017-0411-0 article EN Journal of Infrared Millimeter and Terahertz Waves 2017-07-05

Power consumption in wireless sensor networks is high, and the lifetime of a battery has become bottleneck, restricting network performance. Wireless power transfer with ground mobile charger vulnerable to interference from terrain other factors, hence it difficult deploy practice. Accordingly, novel paradigm adopted where multi-UAV (unmanned aerial vehicle) batteries can information SDs (sensor devices) large-scale network. However, there are discrete events, continuous process, time delay,...

10.3390/rs13132611 article EN cc-by Remote Sensing 2021-07-03

Abstract The heavy metal content in edible oils is intricately associated with their suitability for human consumption. In this study, standard soybean oil was used as a sample to quantify the specified concentration of metals using microwave sensing technique. addition, an attention‐based deep residual neural network model developed alternative traditional modeling methods predicting oils. process data processing, work continued discuss impact depth on convolutional networks. results...

10.1111/1750-3841.17259 article EN Journal of Food Science 2024-08-13

Wireless charging provides continuous energy for wireless sensor networks. However, it is difficult to replenish enough all nodes with fixed alone, and even more unrealistic charge a large number of within short time via mobile charging. In order overcome the above weaknesses, this paper firstly puts forward Master-Slave Charging mode WRSN (Wireless Rechargeable Sensor Network), where master slave mode, respectively. typical hybrid system involving discrete event decision transfer....

10.3390/s21020551 article EN cc-by Sensors 2021-01-14

10.1016/j.physa.2023.128591 article EN Physica A Statistical Mechanics and its Applications 2023-02-21
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