A5101728457- Radio Frequency Integrated Circuit Design
- Advanced Power Amplifier Design
- Microwave Engineering and Waveguides
- Ultra-Wideband Communications Technology
- Laser-Matter Interactions and Applications
- Photonic and Optical Devices
- Full-Duplex Wireless Communications
- Advanced Fiber Laser Technologies
- Indoor and Outdoor Localization Technologies
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Laser Material Processing Techniques
- Advancements in PLL and VCO Technologies
- Food Supply Chain Traceability
- Solid State Laser Technologies
- Gyrotron and Vacuum Electronics Research
- Microwave Imaging and Scattering Analysis
- Optical Systems and Laser Technology
- Antenna Design and Analysis
- Laser Design and Applications
- Advanced DC-DC Converters
- Underwater Vehicles and Communication Systems
- Mass Spectrometry Techniques and Applications
- PAPR reduction in OFDM
- Laser-Plasma Interactions and Diagnostics
Xinjiang University
2024
University of Waterloo
2013-2024
Tongji University
2022-2024
South China Agricultural University
2020-2024
Guangzhou Academy of Special Equipment Inspection and Testing
2022
Soochow University
2020
Xi'an Institute of Optics and Precision Mechanics
2019
Chinese Academy of Sciences
2019
Nanyang Technological University
2009-2012
Southeast University
2012
Laser-induced dissociation and ionization of $\mathrm{H}_{2}{}^{+}$ were simultaneously measured using coincidence 3D momentum imaging, allowing direct separation the two processes, even where fragment kinetic energy is same for both processes. The results 45 135 fs 790 nm pulses with an intensity approximately $2.5\ifmmode\times\else\texttimes\fi{}{10}^{14}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$ differ from each other much more than one would expect previous measurements longer...
The dissociation of $\mathrm{H}_{2}{}^{+}$ in an intense laser field has been experimentally studied using femtosecond pulses at $790\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ the intensity range ${10}^{13}--{10}^{15}\phantom{\rule{0.3em}{0ex}}\mathrm{W}∕{\mathrm{cm}}^{2}$. Kinematically complete measurements both ionic ${\mathrm{H}}^{+}$ and neutral H fragments dissociated from a vibrationally excited beam have achieved by coincidence three-dimensional momentum imaging system. Angular-resolved...
Abstract-In this paper, an ultra wideband impulse radio (UWB-IR) transmitter and receiver monolithic microwave integrate circuit (MMIC) for precision localization sensor network is presented. Longer range achieved with low power consumption at the by fully exploiting FCC's peak constraint efficiently. The MMIC are fabricated on a commercial cost 2 μm GaAs HBT process. output 20 dBm of 0.8 mW 1 MHz pulse repetitive rate. uses non-coherent detection has 44 dB front-end conversion gain....
Ultra low-power radio-frequency identification (RFID) tag with precision localization is often the enabling technology for location-aware sensor applications. Impulse-Radio Ultra-Wideband (IR-UWB) a promising to fulfill usage requirements in indoor cluttered environment. An ultra precise UWB-RFID system proposed this paper. The RFID transmitter comprising of micro-controller board and UWB impulse radio board. Power saving achieved by optimization circuit design short pulses as well...
This brief presents a new approach to cancelling self-interference in full-duplex radios. By augmenting minimal-complexity analog cancellation hardware using radio frequency vector multiplier with the flexibility and effectiveness of digital baseband rational function finite impulse response (FIR) filter, proposed enables excellent performance over wide modulation bandwidth. algorithm is devised by exploiting simplified equivalent behavioral model front-end radio. allows parameters FIR...
This letter presents the design of a 60-GHz power amplifier (PA) using new stacked transformer (STF)-based parallel combiner. It begins by highlighting main limitation conventional millimeter-wave (mm-wave) transformer-based combiners, namely, output parasitic transmission lines. Then, STF combiner based on three overlaying coils is proposed. Analyses revealed significant enhancements in terms self-inductance, quality factors, and coupling which lead to enhanced combining efficiency proposed...
This brief presents a new digitally assisted vector-summing phase shifter (DA-VSPS) featuring high accuracy and enhanced linearity. It begins by highlighting the RF performance degradation of traditional DA-VSPSs operating at millimeter-wave frequencies due to large number unit-cells significant underlying parasitics. Then, DA-VSPS topology is proposed mitigate this source using analog variable-gain amplifiers with current sources. A study linearity conducted inform choice optimal parameters...
This article presents a beamforming Doherty power amplifier (B-DPA) for the 28-GHz fifth-generation (5G) newradio band. The proposed B-DPA is based on new combiner topology that allows current profile in auxiliary branch of DPA to be relaxed while simultaneously canceling amplitude-to-phase (AM-PM) distortion exhibited active devices. approach enables efficiency and linearity enhancements. In addition, augmented with high-accuracy digitally assisted vector multipliers at its input stage...
The strong field ionization of ${\mathrm{Cl}}_{2}$ molecules is investigated by using an ultrashort pulse $\mathrm{Ti}$:sapphire laser. A spatial imaging technique used in such measurements to reduce the effect integration. shows suppression as do other diatomic having valence orbitals with antibonding symmetry $({\mathrm{O}}_{2}{\mathrm{,S}}_{2})$ when compared atoms nearly identical potential. more general molecular tunneling model proposed, and calculations are reasonable agreement...
This paper presents a new millimeter-wave 360 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> digitally-assisted reflection-type phase shifter (DA-RTPS). It is composed of cascade three compact, low-loss and fully-differential transformer-based hybrid couplers with two their ports terminated by switch-controlled capacitor banks. Each stage configured to produce change up 60°. An additional inverting used attain 360° shift. The proposed...
In this article, a real-time digital predistortion (DPD) hardware architecture is presented for the linearization of fifth-generation (5G) transmitters with wideband modulation signals. To overcome bandwidth constraint imposed by maximum clock frequency circuit, new parallel-processing DPD engine devised to allow multiple samples be processed per cycle. minimize complexity and power consumption transmitter-observation-receiver that typically scales bandwidth, an undersampling scheme using...
This letter proposes a uniformly distributed near-field (NF) probing array (NFPA) capable of generating feedback signals suitable for monitoring and improving the performance 5G millimeter-wave (mm-wave) beamforming transmitter. The proposed NFPA configuration is carefully designed to ensure comparable coupling ratios between individual RF chain outputs closest NF probes, across wide frequency range. maximizes quality signal available perform calibration digital predistortion (DPD) when...
This paper presents a stacked push-push frequency doubler using an inductive source degeneration technique for generating high power millimeter-wave signals. A balanced second harmonic trapping matching network is also added at the input to enhance efficiency. The 60 GHz demonstrator, designed 45-nm CMOS SOI technology, showed peak output of 12dBm, DC-to-RF efficiency 20%, and conversion gain 2.1 dB. By applying low-complexity digital pre-distortion scheme, was successfully used generate 200...
This brief presents a wideband compensation method that addresses the hardware imperfections exhibited in an RF vector multiplier (RF-VM) used for predistortion systems. A RF-VM model is first developed to embed various sources of RF-VM. then presented, followed by newly proposed identification algorithm determine parameters modules. Experimental results indicated use can lead improved error magnitude up 10 dB, when generates synthesized signal 150-MHz modulation bandwidth. Furthermore,...
This paper proposes a novel inter-stage load-pull characterization method to enhance the linearity of millimeter wave integrated power amplifiers (PAs) by minimizing their amplitude-to-phase (AM-PM) distortion without worsening AM-AM or efficiency performances. The proposed identifies optimal solution for matching network which enables synthesis driver stage AM-PM characteristic that is complementary stage; consequently, reducing overall PA. technique applied design proof-of-concept 28-31...
Mutlifrequency parametric Raman generation was carried out in a KGd(WO(4))(2) crystal by use of dual-wavelength Ti:sapphire laser system. It found that with femtosecond pump pulses the efficiency is low because onset self-phase modulation. The mechanism for suppression stimulated scattering modulation discussed. Employing 2-ps-long chirped generated four Stokes and one anti-Stokes component.
Cold-storage containers are widely used in cold-chain logistics transportation due to their energy saving, environmental protection, and low operating cost. The uniformity of temperature distribution is significant agricultural-product storage transportation. This paper explored the container by numerical simulation, which included ventilation velocity fan location. Numerical model/numerical simulation showed good agreement with experimental data terms temporal spatial air distribution....
Measurements of laser-induced dissociation H+2 by 135 fs 790 nm pulses with a peak intensity approximately 2.4 × 1014 W cm−2 reveal strong correlation between the angular distribution and kinetic energy released upon dissociation. This is highlighted comparing measured to one expected for photo-dissociation in weak-field limit which has cos2θ distribution. Bond softening aligned along laser polarization much more than photo-dissociation. In contrast, bond hardening results wider...
This letter addresses the very critical challenge facing successful deployment of analog-RF predistortion (ARF-PD) and its hardware implementation complexity. A new envelope memory polynomial (EMP) expression is proposed to alleviate dynamic range requirements for analog multipliers digital-to-analog converters. two-step algorithm devised determine coefficients reformulated EMP within a specified limitation. As proof-of-concept validation, 20 W Doherty power amplifier driven by MHz LTE...
In this letter, a novel linear-in-magnitude RF envelope detector is presented which features high detection speed, low error and covers wide range of carrier frequencies. The proposed topology employs voltage-mode input stage AC-coupled to full-wave rectifier. A prototype was implemented in 0.13 μm CMOS process. Experimental results demonstrated 3 dB operating frequency up 4.2 GHz maximal speed equal 190 MHz. dynamic ( ± 1 linear error) 35.5 at 25.3 3.5 GHz, respectively.