Luoyang Optoelectro Technology Development Center

Luoyang, China

Luoyang Optoelectro Technology Development Center

Luoyang, China
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Chen G.,Luoyang Optoelectro Technology Development Center | Sun W.,Luoyang Optoelectro Technology Development Center | Lv Y.,Luoyang Optoelectro Technology Development Center
Infrared Physics and Technology | Year: 2017

An empirical expression for the energy bandgap as a function of alloy composition x and temperature for In1− xAlxSb was reported. The In1− xAlxSb epitaxial layers were grown by molecular beam epitaxy (MBE) on InSb(1 0 0) substrate, utilizing a p+–p+–n–n+ structure. High resolution X-ray diffraction was used to characterize the epitaxial layers. The Al composition of 2.8% was obtained by assuming the Bragg's formula and Vegard's law. Spectral response measurement of the diodes has been employed to investigate the temperature dependence of the band gap of In1− xAlxSb alloys in the range between 77 K and 260 K. The calculated results for energy gap of InAlSb were in good agreement with the available data and our experimental observation. © 2017


Du B.Y.,Luoyang Optoelectro Technology Development Center
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

Pulse tube refrigerators have demonstrated many advantages with respect to temperature stability, vibration, reliability and lifetime among cryo-coolers for detectors. Double-inlet type pulse tube refrigerators are popular in GM type pulse tube refrigerators. The single double-inlet valve may introduce DC flow in refrigerator, which deteriorates the performance of pulse tube refrigerator. One new type of DC control mode is introduced in this paper. Two parallel-placed needle valves with opposite direction named double-valve configuration, instead of single double-inlet valve, are used in our experiment to reduce the DC flow. With two double-inlet operating, the lowest cold end temperature of 18.1K and a coolant of 1.2W@20K have been obtained. It has proved that this method is useful for controlling DC flow of the pulse tube refrigerators, which is very important to understand the characters of pulse tube refrigerators for detectors. © 2016 SPIE.


Chao M.,Luoyang Optoelectro Technology Development Center | Yang W.,Luoyang Optoelectro Technology Development Center | Jing P.,Luoyang Optoelectro Technology Development Center
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

Infrared Detector Dewar Cooler Assembly (IDDCA) is the key component of infrared system, and the reliability of IDDCA determines the reliability of the system and affects the application of the system to a great extent. Reliability research is of great significance for the engineering application of IDDCA. In this paper, research progress of reliability model, failure modes, acceleration factors, and reliability tests on the assemblies are introduced. Optimizing process and life cycle cost during the manufacturing, and evaluating reliability relying on database are described. In addition, the main thought of reliability research on the assemblies is briefly analyzed. This provides a reference for the domestic reliability research of the assemblies. © 2016 SPIE.


Liu G.,Luoyang Optoelectro Technology Development Center | Jing F.,Luoyang Optoelectro Technology Development Center | Wu Y.,Luoyang Optoelectro Technology Development Center
Proceedings of 2016 IEEE International Conference on Electronic Information and Communication Technology, ICEICT 2016 | Year: 2017

In the research of surface(terrain/sea) clutter calculation, the range-doppler model is employed universally since 1960s, but there are some problems in this method: the complexity of calculation in grid areas, no relationship with antenna pattern and the lack of results in nose-up conditions. In this article, a new self-adapting mesh generation method is presented in surface clutter calculation. In this method, after a rough equi-range-azimuth model used for preliminary mesh generation, the the mesh density will be increased depending on the nonuniformity of pattern gain and backscattering coefficient on the ground. The experimental mean, standard deviation of backscattering coefficients and clutter distribution models are employed to increase the authenticity of the simulation. The result infers that this method is credible and applicable to nose-up, nose-down attitudes and HPRF, MPRF modes. © 2016 IEEE.


Lv H.,Luoyang Optoelectro Technology Development Center | Feng D.-Z.,Xidian University
Proceedings of 2016 IEEE International Conference on Electronic Information and Communication Technology, ICEICT 2016 | Year: 2017

This paper develops a new space-time adaptive processing (STAP) technique for multiple-input multiple-output (MIMO) radar, which is a reduced-dimension application of the well-known factored approach (FA) and extended factored approach (EFA). Simulation results are presented to demonstrate the effectiveness of this new method. © 2016 IEEE.


Zhang Z.,Nanjing Southeast University | Li S.,Nanjing Southeast University | Luo S.,Luoyang Optoelectro Technology Development Center
Aerospace Science and Technology | Year: 2013

The terminal guidance problem for missiles intercepting maneuvering targets with terminal impact angle constraints is investigated. Regarding the target acceleration as an unknown bounded disturbance, novel guidance laws based on integral sliding mode control (ISMC) method technique are developed. The first one is a linear integral sliding mode (ISM) guidance law, which can guarantee the line-of-sight (LOS) angular rate and the LOS angle asymptotical convergence with infinite time. To further improve the convergence characteristics of guidance system, a nonlinear ISM guidance law is developed, which guarantees the LOS angular rate and LOS angle finite-time convergence characteristics. However, to guarantee the guidance system has a good performance for dealing with target acceleration, the switch gains of both linear and nonlinear ISM guidance laws need to be chosen larger than the bound of the target acceleration. It will lead to chattering problem. To reduce the chattering phenomenon and improve the performance of system, nonlinear disturbance observer (NDOB) is employed to estimate the target acceleration. The estimated acceleration is used to compensate to actual target acceleration. Then, two novel composite guidance laws combining linear and nonlinear ISM guidance laws with feedforward compensation terms based on NDOB are developed. Finally, simulation comparison results are provided to demonstrate the effectiveness of the proposed methods. © 2013 Elsevier Masson SAS. All rights reserved.


Zhang Z.,Nanjing Southeast University | Li S.,Nanjing Southeast University | Luo S.,Luoyang Optoelectro Technology Development Center
Transactions of the Institute of Measurement and Control | Year: 2013

For the terminal phase of tactical missiles intercepting maneuvering targets, the terminal guidance problem is studied. Based on an integral sliding mode (ISM) control method and nonlinear disturbance observer technique, a novel composite guidance law is designed in the case of constrained impact angle and a first-order-lag autopilot. Regarding the target acceleration and the external disturbance of autopilot as unknown bounded disturbance, a nonlinear ISM guidance law is designed. The obtained guidance law guarantees the line-of-sight (LOS) angular rate and LOS angle a finite-time convergence characteristics. Then, to alleviate the chattering problem and guarantee the disturbance rejection performance, the composite guidance law combining the ISM guidance law with feedforward compensation terms based on nonlinear disturbance observers is obtained. Finally, simulation comparison results are provided to demonstrate the effectiveness of the presented methods. © The Author(s) 2013.


Lv H.,Luoyang Optoelectro Technology Development Center
IET Conference Publications | Year: 2013

This paper proposes a novel alternating least squares (ALS) method for joint angle and Doppler frequency estimation in bistatic multiple-input multiple-output (MIMO) radar. Via iteratively estimating the transmitting, receiving and Doppler steering vectors of multiple targets from the received signals, ALS can simultaneously obtain the two-dimensional (2-D) angles and Doppler frequency of the target. Simulation results illustrate the rapid convergence rate and high estimation accuracy of this method.


Zhang L.,Luoyang Optoelectro Technology Development Center | Zhang X.,Luoyang Optoelectro Technology Development Center
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

InAs/GaSb superlattice material was grown on GaAs substrates by Molecular-beam epitaxy(MBE). To study the Ohmic contact and electrical property of InAs/GaSb superlattices, the Au//Ti/InAs/GaSb superlattices contact was fabricated using heated electron evaporation methods on the surface of InAs/GaSb superlattices. The Au//Ti/InAs/GaSb superlattices contact character was analyzed by transmission line model. The results show that Au//Ti/InAs/GaSb superlattices contact is the Ohmic contact with good contact resistivity. And it meets requirement of Ohmic contact with the perfect quality. The electrical properties of InAs/GaSb superlattices were tested by Van Der Pauw. That means the leak current decrease as the carriers density reaches to a lower level. At the meantime, the detector obtains a better background noise and energy resolution. © 2012 SPIE.


Guo C.,Northwestern Polytechnical University | Liang X.-G.,Luoyang Optoelectro Technology Development Center
International Journal of Aeronautical and Space Sciences | Year: 2014

This paper proposes a novel guidance law based on the block backstepping sliding mode control and extended state observer (ESO), which also takes into account the autopilot dynamic characteristics of the near space interceptor (NSI), and the impact angle constraint of attacking the maneuvering target. Based on the backstepping control approach, the target maneuvers and the parameter uncertainties of the autopilot are regarded as disturbances of the outer loop and inner loop, respectively. Then, the ESO is constructed to estimate the target acceleration and the inner loop disturbance, and the block backstepping sliding model guidance law is employed, based on the estimated disturbance value. Furthermore, in order to avoid the "explosion of complexity" problem, first-order low-pass filters are also introduced, to obtain differentiations of the virtual control variables. The stability of the closed-loop guidance system is also proven, based on the Lyapunov theory. Finally, simulation results demonstrate that the proposed guidance law can not only overcome the influence of the autopilot dynamic delay and target maneuvers, but also obtain a small miss distance. © The Korean Society for Aeronautical & Space Sciences.

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