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This letter proposes a transceiver integrated multiple-Beam Cassegrain Antenna at 340GHz. The proposed receiving antenna uses a sixteen-channel receiving feed array. Sixteen receiving feeds are misaligned to produce offset beams, and each of them is received individually, which simplifies the structure and provides flexibility for signal processing. The proposed transmitting antenna and receiving antenna are coaxial. The main reflector of the parabolic transmitting antenna is connected with the receiving antenna’s sub reflector, thereby improving the space utilization and the robustness. Sixteen-beam Antenna ensures a large-angle scanning, and works stably within a bandwidth of 25GHz. The main lobe gain is greater than 55dB, 3dB beam-width varies around 0.16° and the sidelobe levels are lower than -24dB for all the beams. The proposed antenna shows an excellent radiation performance which can meet the needs of RF front-end of the situational awareness system.

Friction between meshing gears is one of the principal exciting sources of vibration in gears. Numerous literature have been devoted to investigate the influence of friction on the system. In this article, a new analytical model of a gear transmission system with time-varying meshing stiffness, viscous damping and friction torque is studied to examine the significance of sliding friction on system response and stability.

Detection of the wire rope directly relates to the personal and equipment safety. However, detection of the wire rope is confronted with some problems at present. For example, the detection result is affected by the running speed, the detection distance and the environment, the detection accuracy is not high, the versatility is not strong and so on. Therefore, key techniques of pretreatment and quantitative identification of broken wire detection signal in wire rope need to be studied. The study contents include the method of obtaining damage signal of wire rope broken wire, the pretreatment method of broken wire signal of wire rope, the detection signal feature extraction and quantitative recognition method and the key technology and implementation of detection software development. This study is of great significance to improve the safety of wire rope use.

Objective: To observe the effect of changes in functional residual capacity（FRC）on the severity of patients with obstructive sleep apnea hypopnea syndrome (OSAHS). Methods: A total of 256 patients with OSAHS diagnosed by night polysomnography (PSG) were enrolled, including 208 males and 48 females. The patients were recorded with sleep hypopnea index (AHI), oxygen reduction index(ODI), arousal index(ArI), total sleep time(TST), maximum apnea time(MAT), average apnea time(AAT), mean oxygen saturation (MSaO2), lowest oxygen saturation (LSaO2), oxygen saturation below 90% of the total recording time (TP90%) and other indicators. All subjects underwent pulmonary function tests to measure residual lung volume index (RV), functional residual capacity (FRC), and total lung volume (TLC). All subjects were divided into three groups in terms of less than or equal to 80%, 80% to 110% and greater than 110%. The sleep related indexes such as AHI, ArI, ODI, TST, MAT, AAT, MSaO2, LSaO2 and TP90% were compared among the groups. Results: In the case of similarity in sex, age, BMI, and degree of pharynx ( no statistically significant difference between groups), AHI, ODI, ArI, MSaO2, LSaO2 and TP90% were statistically different between groups(P 0.05). Conclusion: The patients with OSAHS whose functional residual capacity is higher have a relatively milder condition. The increase of functional residual capacity can improve the degree of upper airway collapse and increase the stability of upper airway, thus improving severity of OSAHS patients.

This paper presents the design and simulation of a three-stage monolithic millimeter-wave integrated circuit (MMIC) amplifier with a 70-nm InAlAs/InGaAs/InP pseudomorphic high electron-mobility transistor (PHEMT) technology. The three-stage MMIC amplifier is designed through schematic simulation and momentum EM co-simulation by ADS software with a 2×25 μm gate length PHEMT. The high-low pass filter structures are used for matching network, edge-coupled lines are selected to block dc voltage, radial stubs are chosen as RF ground and shunt RC networks are included in the bias circuitry to maintain amplifier stability. Ground coplanar waveguide (GCPW) structure is added in input and output port. The three-stage MMIC amplifier demonstrates a maximum small-signal gain of 17.8 dB at 150 GHz along with a 3dB bandwidth of 90 GHz, return loss is better than 5 dB in operating frequencies, and the size is about 2.3×1.2 mm2.

The paper proposed a cavity-coupled vertical transition structure working at 110 GHz. Two mode-transition units were fabricated at ends of a vertical metal cavity symmetrically, acting as two excitation ports of a waveguide. The proposed mode-transition unit was realized on a 50-μm thick quartz-substrate with via holes and double-side patterned. In this way, the vertical transition structure presented a low insertion loss at terahertz frequency. Good agreement between simulated and measured results was obtained. The simulated S21 of the mode-transition unit was −0.7 dB, the measured S21 was less than −1.3 dB. The bandwidth from 105 GHz to 116 GHz was obtained for reflection level lower than −10 dB.

This paper presents the design and simulation of a D-band active integrated frequency-doubler MMIC with a 70-nm InAIAs/lnGaAs/lnP pseudomorphic high electron-mobility transistor (PHEMT) technology. The doubler MMIC is designed through schematic simulation and momentum EM co-simulation by ADS software with a 2×25μrn gate length PHEMT. Without the use of post-amplification, the frequency-doubler generates an output power more than 0 dBm range from 135 to 165 GHz with an input power of 4.5 dBm, that is, a 3-dB bandwidth of 20% has been achieved. The maximum output power of 1.58 dBm at 143 GHz. At the same frequency, the MMIC exhibits a conversion gain up to -2.9 dB, with high suppressions of 21.6 dB, 33.7 dB on the fundamental, and the third harmonics respectively. The total DC consumption of frequency-doubler MMIC is about 19.6 mW.

Based on the characteristics of shallow buried, non-trap structure and close cover, non-diagenesis, weak cementation and easy fragmentation of natural gas hydrate deposits in China, a solid fluidization well testing and production scheme to develop these kind of natural gas hydrate is proposed. The main idea is to transfer the non-diagenetic natural gas hydrate sediments buried in shallow layer of deep-water into a closed multi-phase transporting and lifting system through mechanical crushing fluidization, during the lifting riser system from seabed to surface, hydrate will be dissociated gradually based natural rule of sea water temperature rising and the hydrostatic pressure decrease with the change of water depth during the lifting process, to turn the uncontrollable decomposition process of non-diagenetic hydrate into controllable, and to achieve safe field exploitation of natural gas hydrate in the surface and shallow layer of deep-water. After the validity was verified by the laboratory experimental study, CNOOC successfully implemented the world's first solid fluidization well testing and production of marine non-diagenetic hydrate with the water depth of 1310m and the hydrate sediments layers 117~196m depth in May 2017. It means China has found an innovation way about natural gas hydrate exploration and development with self-developed key technology and tools. The implementation relied on the Deepwater Engineering & Survey Vessel "HYSY708" at the station of Li Wan 3 in the South China Sea and it was supported by fully self-developed technology, process and facilities.

This paper presents the design and simulation of a three-stage driver amplifier with a 70-nm InAlAs/InGaAs/InP pseudomorphic high electron-mobility transistor (PHEMT) technology. The three-stage driver amplifier is designed through schematic simulation and momentum EM co-simulation by ADS software with a 2×25 μm gate length PHEMT. The high-low pass filter structures are used for matching network, edge-coupled lines are selected to block dc voltage, radial stubs are chosen as RF ground and shunt RC networks are included in the bias circuitry to maintain amplifier stability. Ground coplanar waveguide (GCPW) structure is added in input and output port. The three-stage driver amplifier provides more than 18dB linear gain between 90 and 120GHz, a P-1dB at the output of 7dBm, more than 10dBm saturated output power at 110GHz, consumes 58.9mW and the size is about 2.3×1.1 mm2.

With the emergence of a variety of data cloud services, especially composite data cloud services, service trustworthiness problem is particularly prominent. Data cloud service credibility becomes focus of cloud service consumers. Data cloud service is essentially a Web service and its quality is associated with the Web service evolution process. In this paper, considering how provenance information, a trustworthiness calculation method for the output data trustworthiness calculation of composite Web service is proposed. In this method, Two specific work are completed. One is that the rules are given for calculating the trustworthiness with their correctness proved. The other is that the evolution model of the composite service is built, and the SP-binary-tree for the execution process of the composite service is completed. Finally, the proposed method is verified to be feasibility and effectiveness through examples of application.

Along with the comprehensive advancement of education informationization, knowledge management (PM) is also researched unceasingly in the educational technology, it becomes a hot topic of discussion in this domain that how to gain, use, management and innovate effectively knowledge. The teacher and the student who are two big communities in the education domain are the centre of attention in personal knowledge management. At present, the harvest of personal knowledge management research is hardly abundance at home and abroad. The relevant theoretical systems are needed to be improved. Especially the personal knowledge management (PKM) for the student is the condition of starting. The theory of the personal knowledge management for the student and system's development, which are mainly discussed in this thesis, have important practical significance and application value.

This paper presents the design of a four-stage monolithic amplifier with a 90-nm InAlAs/InGaAs/InP pseudomorphic high electron-mobility transistor (PHEMT) technology. The PHEMT (0.09 × 2 × 25um2) have a dc transconductance (gm) of 1640 mS/mm with f t >200GHz and f max >300GHz. The four-stage monolithic amplifier is designed through schematic simulation and momentum EM co-simulation by ADS software. The high-low pass filter structures are used for matching network, edge-coupled lines are selected to block dc voltage, radial stubs are chosen as RF ground and shunt RC networks are included in the bias circuitry to maintain amplifier stability. Ground coplanar waveguide (GCPW) structures are added in input and output port. This amplifier demonstrates a small-signal gain of 24.7 dB at 105 GHz and greater than 21.5 dB gain from 84 to 114 GHz.

An 85–115 GHz three-stage monolithic millimeter-wave integrated circuit (MMIC) amplifier based on 90-nm InAlAs/InGaAs/InP pseudomorphic high electron-mobility transistor (PHEMT) devices has been designed. The PHEMT (0.09×2×25um2)used in this design has a dc transconductance (gm) of 1640 mS/mm with ft =247 GHz and fmax=392 GHz. The monolithic three-stage amplifier demonstrates a small-signal gain of 18.7 dB at 105 GHz and greater than 15.5 dB gain from 85 to 115 GHz. This amplifier is designed through schematic simulation and momentum EM co-simulation. In this design, the high-low pass filter structures are used for matching network, edge-coupled lines are selected to block dc voltage, radial stubs are chosen as RF ground and shunt RC networks are included in the bias circuitry to maintain amplifier stability. Ground coplanar waveguide (GCPW) structures are added in input and output port.

the paper proposes an online-public-key cryptographic scheme for data security in bridge health monitoring. The scheme solves the problem such as how to preserve and manipulate the users’ private key securely. Meanwhile, it realizes the mutual authentication between user and server, in which the private key splitting method is proven to be secure in the RO model. The analysis shows that the scheme is able to resist the normal attacks such as the denial of service or the off-line password guess effectively. It has strong robustness in applications.

This paper analyzes a brand-band coplanar waveguide (CPW) to slotline transition using slotline ring only in THz band, which is a useful component in uniplanar MMIC applications. Two different types of air bridges were studied, which could suppress the slotline mode in CPW and widen the bandwidth. The paper shows a slotline ring fed by CPW printed in the center conductor of the CPW. Compared with the slotline ring printed in the ground plane, the proposed transitions have additional degrees of freedom, wider bandwidth and reduce the number of air bridges.

In this paper, issues a novel Flip-chip (FC) package model simulation of THz on a chip integrated antenna. Log periodic antenna is designed on a GaAs substrate, with a thickness of 100 μm. An air bridge of Schottky Diode located at the center of the antenna is protected by using thin-film ceramic layer for supporting layer. About 200 μm diameter Au pad on GaAs substrate is connected to the PCB board via thin-film ceramic layer. There is an air chamber underneath the antenna to improve antenna performance and mitigate multilayer structure influence the near filed of antenna. The FC package mode cause simulation results performance to deteriorate. Nevertheless, good performance has been obtained up to around 0.25–0.34 THz (λ=1200μm-880μm). Thus, FC processing with thin-film ceramic layer has been proven to be one solution for THz region antenna package. Which can give simplicity and possibility of designing large format arrays on a direct detection or heterodyne detection THz system.

In this paper, a 110GHz power divider/combiner based on microstrip branch-line hybrid is proposed, which can form a power splitting/combining network. This quadrature hybrid has the properties of low loss, equal power splitting, mature microstripprocessing technology, especially can be tested on chip. In the whole band(105GHz∼115GHz), the 3D EM simulation results show that the return loss is less than-19.78dB (−34.49dB at 110GHz); between the outputs, the magnitude difference is less than 0.05, while the phase difference is less than 0.3°, also the output isolation is more than 19.94dB (35.06dB at 110GHz). Integrated with MMIC power amplifiers, this divider/combiner can be widely used in W band power combining systems.

Cell range extension (CRE) has been used as a method to extend the coverage of small cells and help offload macro cell users to small cells by adding a cell specific offset (CSO) to small cells in heterogeneous network deployment. However, previous literatures only considered CSO setting in sparse small cell networks (SCN) deployment where the number of small cells is relatively small. In this paper, we have studied the influences of different CSO values in SCN environment with a very dense deployment of small cells and analyze CSO value setting preference in this scenario. A bias setting algorithm has been proposed to adjust the CSO so as to alter the coverage area of SCNs to achieve the optimal average user throughput. Simulation results indicate that this method can achieve a better average user throughput in networks with different densities of small cells.

The short impedance standard is the easiest fabricated in Open-Short-Load (OSL) calibration method for on-wafer scattering parameter (S-parameter) measurement. The fabrication and the definition of the other two impedance standard are more questionable. A new extraction method is presented to determine short inductance of coplanar waveguide (CPW) probe. Based on this consideration, other open capacitance and load inductance in OSL calibration method are compensated. The method needs only imperfective OSL impedance calibration kits and another standard offset short. It may improve on-wafer S-parameter accuracy of OSL calibration, which is the same as Thru-Reflect-Line (TRL) calibration. The experimental verification of the new estimation algorithm is given by using the designed and fabricated OSL calibration kit and standard offset short on Al2O3 substrate up to 50 GHz.

An integrated THz filtering antenna of AIP (antenna in package) is proposed. As the indispensable parts of THz AIP, antenna and filter are designed together and fabricated by MEMS (Micro-electromechanical System) technology on silicon substrate. A MEMS H-plane horn antenna from 400GHz to 500GHz is designed as AIP antenna element, and a well designed E-plane metallic-via filter is chosen as filter element. The good performance of this filtering antenna is shown by the simulated results. A photomask of filtering antenna with other AIP devices is made to prove the feasibility of this design. (4 pages)

In order to effectively improve the identification precision of the submersible motor temperature sensorless, The long cable parameter perturbation analysis theory is applied to the submersible motor temperature identification, Firstly this paper uses the distributed parameter method for the analysis of cable parameters distribution, then building and simplifying the model of long cable, rotor and stator in the submersible motor with SolidWorks. Because SolidWorks and ANSYS has a good interface, which can be sheathed cables, submersible motor model into ANSYS, therefore we can get the submersible motor and cable's temperature distribution maps by using the ANSYS thermal field analysis function, finally comparing the simulation results with the measured data to verify the theory that is presented in this paper.

This paper presents a simple precision slab-line for N type coaxial automatic tuner. The precision slab-line in N type coaxial automatic tuner is firstly calculated by conformal mapping principle. Then, the transition section between coaxial transmission line and slab-line is optimized using misalignment compensation method. The dielectric support included in the precision coaxial adapter is also designed by coplanar compensation law. Finally, these three modifications are utilized to achieve the overall improvement slab-line with very well match in the designed frequency-band. The measured VSWR results are better than 1.10 from 1GHz to 10GHz using the vector network analyzer.

Rotor bar broken fault is one of the common faults of the submersible motor. In order not to affect the production efficiency of submersible motor, the fault should be detected in time. For the purpose of solving the problem of the rotor crack detection, this dissertation has designed a method based on the analysis of the stator current to detect the rotor bar breaking fault. Through the experiments on submersible motor, we analyze on the stator current spectrum by means of HHT algorithm of the three different states of submersible motor—normal, minor fault and complete fault, and discriminate the fault in accordance with the frequency and amplitude of the current spectrum. Furthermore, the BP neural networks are also applied into the research to identify the rotor bar breaking fault in order to increase the accuracy of the discrimination results. The experiment and the research end up with a better result, and it verifies the feasibility and accuracy of the method.

An automatic measurement system for traceable characteristic impedance of coaxial air lines is introduced. The system is used to measure conductor diameters of air lines with precision connectors. It is composed by inner diameter of outer conductor (IDOC) and outer diameter of the inner conductor (ODIC) measurement setup. In this system, a new automatic measuring technology with capacitance sensor is established for IDOC. As an example, the measurement results of three 2.4mm air lines are shown. Analysis on the uncertainty of conductor diameters and characteristic impedance of coaxial air lines is given finally.

An improved automatic measurement setup for measuring inner diameter of outer conductor (IDOC) in coaxial air lines with precision connectors, including N, 7 mm, 3.5 mm, 2.92 mm, 2.4 mm, and 1.85mm, is introduced. The improved setup can accurately measure the straightness and the position of measured cross-section of IDOC. Multi-gauge calibration method and orthogonal regression algorithm are used to achieve measurement uncertainty smaller than 0.3µm. As an example, the measurement results of air lines with precision 2.92 mm and type N connectors are shown.

An automatic measurement setup for measuring outer diameter of the inner conductor (ODIC) of coaxial air lines is introduced. The setup is used to measure ODIC of air lines with precision connectors, including N, 7mm, 3.5mm, 2.92mm, 2.4mm, 1.85mm, 1.0mm. Multiple needle gauges are used to achieve measurement uncertainties better than 0.3μm. As an example, the measurement results of 2.92 mm and 1.85mm connector air lines are shown.

This paper briefly reviewed the integrated antenna in terahertz (THz) imaging system, and analyzed the requirements of antenna performance in THz a focal-plane imaging array design. A type integrated active antenna was researched, which was composed with planar antenna integrated with GaAs Schottky diode and a dielectric integrated lens, which was used to enhanced the planar antenna radiation performance. A hybrid simulation method combined with FEM, PO and GO was utilized in antenna analysis. A broadband integrated detector antenna (30∼110 GHz) was fabricated and tested. The measurement results agreed with simulation results well. Two kinds of active antenna array were proposed and analyzed for THz focal plane imaging system.

Time-frequency imaging methods include many base functions, it is hoped that the best can be applied in two dimensional imaging. A experimental radar system is designed. STFT, WVD Harr and morlet wavelet transforms are simulated and compared, which shows WVD has the best quality of the ISAR images.

A base band sum-difference scenario used in digital monopulse radar system is introduced in this paper. The angle measurement error caused by the amplitude and phase imbalance of the receiving channels is also analyzed based on this system structure. A digital calibration method as well as the compensation result is represented.

This paper presents a hybrid Schottky diode model for mixer design. The model consists of two parts: the passive part and the active part. The passive part is built according to the dimensions of the diode which can be analyzed by EM simulator and the active part is built according to the I-V characteristic which can be analyzed by harmonic balanced simulator. Based on the proposed model, a W-band Subharmonically pumped mixer was designed, whose conversion loss is below 14 dB from 85 GHz to 93 GHz.

2.24 w power-amplifier (PA) module at 35 GHz presented using broad-band spatial power-combining system. The combiner can accommodate more monolithic microwave integrated-circuit (MMIC) PA with stagger placement structure on limited microstrip space in Ka-band waveguide structure with good return losses, and heat can dissipated into aluminum carrier quickly. This combiner is based on a slotline-to-microstrip transition structure, which also serves as a four-way power combiner. The proposed 2*2 combining structure combined by vertical stacking inside the waveguide was analyzed and optimized by finite-element-method (FEM) simulations and experiments.

X band and Ka band front-ends are integrated into one measurement system in order to get radar cross section and images of complex objects, software defined radio is applied in system design. Then ISAR processing technology is investigated to gain two dimension scattering centers distribution and radar cross section imaging and CBP algorithm is verified to obtaining object information efficiently.

The implementation of integrated hardware-in-the-loop (HWIL) simulation and testing system for millimeter-wave (MMW) seeker was presented. The system can implement dynamic real-time testing for MMW seeker. The seeker's ability of detecting, identifying and tracking the target, can be checked and tested in a realistic flight scenario. The system configuration is described, and the implementation of its chief components was proposed which are the MMW scene generator, the high speed data acquisition subsystem, and the central control unit. This system could be applied to the simulation and testing of some types of MMW seeker which are on development.

This work aims to apply Computational Fluid Dynamics (CFD) and Computational Structural Dynamics (CSD) to simulate the interactions between unsteady compressible flow and immersed moving and/or deforming solid structures. The main challenge is due to the fact that fluid dynamics, structural dynamics and their interactions are highly nonlinear, multiscale and multiphysical phenomena. In this work, an efficient and accurate numerical simulation package, incorporating solution methods for both three dimensional Navier-Stokes (NS) and structural dynamic equations, has been successfully developed and validated. The baseline method is a finite-volume scheme using unstructured grids. Such features ensure the convenient and accurate modeling of complex geometries. A 3rd-order high-resolution edge-based Roe approximate scheme is adopted in the NS solver to accurately capture the possible existence of shock in highspeed flow regions, while cell-based 2nd-order Galerkin-type formulation is used to calculate the variable gradients. For temporal integration, a novel matrix-free implicit dual time-stepping is adopted. To simulate turbulent flows, a novel mixed dynamic formulation of eddy-viscosity subgrid model based on Smagorinsky-Lilly method has been integrated into the Large-eddy simulation module of the package. To couple the NS and structural dynamics solvers more efficiently, the immersed membrane method (IMM) is adopted and enhanced to handle the fluid-structure interaction. DOCTOR OF PHILOSOPHY (MAE)

According to software defined radio theory, Four Sections and Four layers Architectures for radar target signatures measurement are presented and researched, which can be applied to design to get more and more information including RCS or multi-scattering centers distribution etc. Versatile radar signals can be used in the measurement system, and the working frequency band and bandwidth are changeable, therefore, it is necessary for the design to update signal processing algorithms. The tradeoffs will be analyzed for measurements, the SDR measurement platform is designed, In the end, some characteristics of a complex target will be showed by experimental data.

In this paper, a modularization method for analyzing the microwave performance of the electrode is illuminated. As an example, a CPW electrode of LiNbO/sub 3/ electro-optic modulator with a bandwidth of 12 GHz is designed, and the simulation results indicate that this method is feasible in practice. The modularization method can greatly reduce the computation time, improve the design accuracy, mostly avoid transmission discontinuities and be in favor of the following optimization.

A broadband adaptive array antenna system was built in lab to check the signal processing algorithm. The antenna element, the RF receiving module and the digital processing unit are presented step by step. Especially for the signal processing, both the hardware platform and the software algorithm are researched together. In multiuser circumstances, a decorrelating detector is usually adopted to detect multiuser, here a novel CSS algorithm is presented according to CDMA communications system requests.

While stealth technologies for large scale targets were researched, RCS static measurement method was adopted, which is often used under non-far field condition. Therefore a theoretical premise was deduced, and a stepped frequency pulse compression system was designed for RCS measurement, especially a novel RF channel was designed to keep the system stable. Not only the simulation but also the experimental result is presented LU the paper; at the same time, some practical difficulties are designated.

To overcome the defects of metamaterials, such as high dispersion, the high loss, and the problem of homogenization, we design and implement an active tunable metamaterial transmission line, and measure the characteristics of active tunable metamaterial transmission line that is based on lumped elements and negative differential devices. From the measured results, it exhibits not only electronically tunable scattering parameters (electro-control tunable characteristic) but also the negative attenuation constant (the propagation amplification) in the left-handed frequency band (active characteristic).

This paper presents a practical and efficient design for a microstrip array antenna with beam squint. Its essential method is using a special feed network. Then the amplitude distribution on the array's aperture is tapered from the center to the ends, and the aperture phase is shifted from one end to the other. A microstrip array antenna with beam squint is developed, which shows that the design is correct.

A strategy is presented to acquire active terahertz (THz) metamaterial by incorporating negative differential resistance carbon nanotubes. Furthermore, we propose a method of extracting active metamaterial effective parameters. This new method can effectively solve the problems of signs and multi-branches, while the traditional parameter extraction method becomes powerless for active case. Our results indicate that the active THz metamaterial with metal wires array not only has negative value of the imaginary part of the permittivity but also presents magnetic-dispersion characteristics.