Abstract:

To address the issue of high freewheeling losses caused by SiC Metal-Oxide-Semiconductor Field-Effect Transistors(MOSFETs) during the freewheeling process in power modules, an integrated Low-Barrier Diode SiC MOSFET(LBD-MOS) structure is proposed. The total power consumption of LBD-MOS and the conventional SiC MOSFET(CON-MOS) under the same area is investigated. Simulation results show that the freewheeling voltage drop(U_F) of LBD-MOS is 1.6 V, which is 50% lower than that of CON-MOS; the switching loss (E_switch) of LBD-MOS is 187.3 μJ, which is 6% lower than that of CON-MOS. Under operating conditions with a frequency of 10 kHz and a duty cycle of 50%, the total power consumption of LBD-MOS is reduced by 22.6% compared to that of CON-MOS. LBD-MOS is suitable for applications where the freewheeling ratio is higher than 50% and the switching frequency does not exceed 1 MHz.

Abstract:

The heteroepitaxial process of Gallium Nitride High Electron Mobility Transistors (GaN HEMTs) leads to the presence of a trapping effect in GaN HEMT devices. This effect causes dynamic changes in the on-resistance of the devices under continuous transient operating conditions, known as dynamic on-resistance, which is higher than the theoretical value under static conditions. This dynamic on-resistance can pose a threat to the stability of power systems. Therefore, it is necessary to investigate efficient and accurate testing methods for the dynamic on-resistance of GaN HEMT devices. The mechanism of dynamic on-resistance generation in GaN HEMT devices is introduced in this paper. In combination with practical testing requirements, a novel clamping circuit based on an ultra-high-speed voltage feedback operational amplifier is designed. The Pspice simulation tool is employed to simulate this new clamping circuit and compare it with other commonly used existing clamping circuits. The results show that this circuit can more rapidly and accurately read the drain voltage of the device after it transitions from the off-state to the on-state. It also enables the characterization of the device's on-resistance under different bias voltages and frequencies.

Abstract:

In recent years, significant progress has been made in the development of domestic 6-inch SiC-based Gallium Nitride High Electron Mobility Transistors(GaN HEMTs). This paper investigates the multi-layer dielectric stress modulation technique and high-consistency backside etching technique, which are integrated into the 6-inch process. When operating at 48 V, the 0.5 μm process achieves an output power density of 8.6 W/mm at 3.5 GHz, with a power gain of 15 dB and a Power Added Efficiency(PAE) of 58.5%. When operating at 28 V, the 0.25 μm process achieves an output power density of 5.5 W/mm at 10 GHz, with a power gain of 8.7 dB and a PAE of 55.2%. The reliability of GaN devices is evaluated through High-Temperature Operating Life (HTOL) and High-Temperature Reverse Bias(HTRB) tests, with the saturation output current of the devices changing by less than 10% after 1 000 hours. The 20 W and 40 W power transistors, as well as X-band Monolithic Microwave Integrated Circuit (MMIC) power amplifiers, are fabricated to validate the process technology, with measured on-wafer yields of 90%, 86%, and 77%, respectively. The results indicate that domestic6-inch SiC-based GaN HEMTs have application potential below the Ku-band.

Abstract:

The working principle of a nanosecond-level high-voltage pulse generation circuit based on a Drift Step Recovery Diode(DSRD) is introduced. The circuit is modeled, and the key circuit parameters that affect the pulse output characteristics are discussed based on the model. In the experiment, a high-voltage Silicon Carbide(SiC) DSRD device developed in the author's laboratory is employed to generate a nanosecond-level pulse voltage with a peak value of 2.27 kV and a rise time of 1.846 ns on a standard load of 50 Ω. By changing the key parameters in the circuit, the variation trends of the pulse voltage peak obtained from the tests are consistent with the analysis from the model, which validates the rationality of the model. Considering the voltage overshoot issue at the drain-source terminals of the switch during the turn-off process, a buffer capacitor is connected in parallel across the drain-source terminals. The parameters of the buffer capacitor are adjusted experimentally to reduce the overshoot voltage at the drain-source terminals without affecting the peak voltage of the DSRD pulse discharge.

Abstract:

Based on the GaAs substrate Enhanced/Depletion-mode pseudomorphic High Electron Mobility Transistor(E/D pHEMT) process, a three-bit adjustable 1 400 ps Digital-Controlled Delay (DCD) chip operating in the 0.5~6 GHz frequency range has been developed. The chip measures 3.60 mm ×4.00 mm ×0.07 mm and integrates a three-bit digital-controlled delay line and a 3-bit parallel port drive circuit. Within the 0.5~6 GHz range, the DCD chip exhibits insertion loss of less than 11 dB, with insertion loss variation of less than ±0.5 dB. The Voltage Standing Wave Ratio(VSWR) for both input and output is less than 1.5 across all states. The 1 400 ps delay error can be internally adjusted to ±4 ps, achieving a delay quantity at the nanosecond level. By incorporating additional adjustable units and bonding cut-off methods, the delay accuracy is enhanced to 3‰. The chip features broadband operation, high precision, large delay quantity, and a compact size, making it well-suited for applications in antenna systems.

Abstract:

A novel Avalanche Triggered MOS-Controlled Thyristor(AT-MCT) is proposed, which achieves high current peak, high current rise capability (di/dt), and non-activation protection in the non-operating state during capacitor pulse discharge. The device incorporates a highly doped N Avalanche Layer(N-AL) buried in a Pbody, with an N+ region near the cathode separated from the MOS structure. When a gate voltage is applied, the channel generated by the MOS transfers the potential of the N-drift region to the N-AL. The highly doped N-AL experiences avalanche due to the electric field peak, and the generated electron-hole pairs serve as the base current of the thyristor, enabling the AT-MCT to rapidly establish a self-feedback mechanism. Meanwhile, the positive feedback process established by the avalanche significantly improves the two-dimensional transient carrier transport effect, increases the effective conduction area of the cell during transient turn-on, and thus achieves more efficient energy conversion. The AT-MCT exhibits a 40% increase in current peak and a 31% increase in di/dt capability compared to Cathode-Shorted MCT(CS-MCT). Moreover, by designing the doping concentration of the N-AL, non-activation protection in the non-operating state can be realized, thereby enhancing the reliability of the pulsed power system.

Abstract:

The performance and defect detection of Low-Emissivity(Low-E) glass are of great significance in its production. Currently, for Low-E glass with single, double, or multiple silver coatings, defect detection mainly relies on the analysis of visible light images, which presents certain limitations such as insufficient contrast and low identification efficiency. Terahertz waves can penetrate most non-conductive materials, making them highly effective for internal defect detection and structural analysis. Therefore, in this study, Terahertz Time-Domain Spectroscopy(THz-TDS) and scanning imaging technology based on this principle are employed to detect the coating structure and surface scratches of Low-E glass. By utilizing reflective THz-TDS and scanning imaging techniques, the waveform and intensity of the reflected terahertz pulse signals from glasses with different coating structures are investigated and the defect imaging is successfully achieved. This study demonstrates the feasibility of THz time-domain spectroscopy in the identification of glass coatings and defect detection.

Abstract:

Based on an ultrashort H-plane coupler and a cut-off structure, a high frequency structure of a W-band Periodically Cusped-Magnetic(PCM) field focused wideband sheet-beam Traveling-Wave Tube(TWT) is shortened by 27.7 mm. This approach allows the TWT to generate more than 200 W of power within a bandwidth of 13 GHz(90~103 GHz). The interaction between the electron beam and microwave in the ultrashort cut-off structure is investigated. The study shows that the ultrashort cut-off structure can mitigate the divergence of bunched electrons at the cut off structure when the first section of the Slow-Wave Structure(SWS) is long enough, thereby significantly enhancing the output power and bandwidth of the TWT. Therefore, long cut-off structures, high input signal voltages, and low electron gun voltages should be avoided when a wideband TWT is designed.

Abstract:

To enhance the angular stability of Frequency Selective Surface(FSS) absorbers, a broadband absorber is designed by using an Indium Tin Oxide(ITO) resistive film in combination with a dielectric compensation layer. This absorber features flexibility, transparency, polarization insensitivity, and high angular stability. The 90% absorption bandwidth of the absorber covers the frequency range of 5.66 to 22.98 GHz, achieving a relative bandwidth of 121.0%. When the incidence angle of the electromagnetic wave varies from 0° to 60°, the absorber maintains an absorption rate of over 80% in the frequency band of 7.00 to 22.86 GHz. Fabrication and experimental testing have shown that the designed FSS absorber exhibits good transparency and flexibility, with test results matching well with simulation results, thereby validating the rationality of the design. Moreover, when the sheet resistance of the resistive film and the relative permittivity of the dielectric layer fluctuate within certain ranges due to manufacturing processes, the absorber structure can still achieve broadband absorption and maintain high angular stability. This significantly enhances the engineering practicability of the designed absorber in applications such as stealth and electromagnetic interference suppression for the windows and doors of aircraft and vehicles.

Abstract:

A dual-band amplitude and phase dual-regulation metasurface is proposed to achieve arbitrary beamforming shapes at two preset frequencies. By combining two resonators of different sizes in the metasurface unit, independent amplitude and phase control can be realized at the two frequency points. Under linear polarization excitation, amplitude regulation is achieved by rotating the resonators, while phase regulation is realized by changing the size of the resonator openings. An improved array synthesis algorithm, combining Taylor synthesis and genetic algorithm, is employed to obtain far-field patterns that closely match the desired shapes. The resulting phase range is relatively small, which is conducive to achieving high-efficiency array beamforming. A metasurface array that can generate a flat-top beam at 6.25 GHz and a cosecant-squared beam at 15 GHz is designed. The full-wave simulation results show that the beams generated by the designed metasurface array match the target beams very well, with low sidelobe levels. This work provides a new approach to far-field array beamforming using dual-band metasurfaces.

Abstract:

To investigate the potential damage caused by High-Power Microwave Weapons(HPMW) attacking radar systems through exposed cable backdoors, a cable model between radar units is established. The effects of different cable types, installation heights, electric field directions, and cable lengths on coupling signals are compared and analyzed. The characteristics of coupling signals are measured through irradiation experiments, and the impact of coupling signals on radar is analyzed. Corresponding protective circuits are designed, and other protective measures are discussed. Theoretical analysis and experimental results indicate that the peak voltage and waveform of the coupled signal are greatly affected by factors such as cable type, installation height, and electric field direction, while the resonant frequency of the coupled signal is greatly affected by cable length. The threat of coupling signals can be reduced through technical protection measures and reasonable cable layout.

Abstract:

High-gain DC/DC converters have a promising application prospect in new energy generation and DC microgrids, and good dynamic characteristics are the foundation of their applications. Compared with traditional switching converters, high-gain converters face challenges such as high computational complexity and high model order in modeling. A new modeling method is proposed for high-gain converters based on system identification. It analyzes the working principle of the three-winding Boost?Forward converter and establishes a small-signal model of the converter using the state-space method. The correctness of the established model is verified through simulation. The sources of modeling errors in the state-space method are analyzed. The small-signal model of the converter is initially extracted using the least squares method, with a system model accuracy of 91.43%. Subsequently, an improved Particle Swarm Optimization(PSO) algorithm is employed to accurately extract the small-signal model, achieving a system model identification accuracy of 94.62%. Numerical experimental results demonstrate the correctness of the proposed identification method. The results have high reference value for the modeling and control loop design of complex converters.

Abstract:

Aiming at the problem that existing jumping robots cannot precisely control their jumping posture angles, a posture control method for jumping robots based on flywheel reaction force regulation is proposed. During the jump, the reaction force generated by the continuous rotation of the flywheel can be utilized to adjust the robot's posture angle. Each flywheel regulator is controlled using a fuzzy adaptive Proportional-Integral-Derivative(PID) controller. Compared with traditional PID controllers, fuzzy adaptive PID can more quickly adjust the robot's posture angle with smaller tracking errors.Simulation results show that, compared with traditional posture control methods, using flywheel regulation can achieve real-time control of the jumping robot's posture angle more quickly. Especially during continuous jumping, the flywheel can better absorb intermittent impact momentum, allowing the robot's posture angle to remain stable over a larger range. In future work, a physical prototype of the jumping robot will be considered for construction to conduct obstacle-crossing tests in both indoor and outdoor environments.

Abstract:

To address the issue of high implementation complexity in compensating for nonlinear distortion in short-range optical fiber communication systems using Intensity Modulation and Direct Detection(IMDD), a method based on an Adaptive Artificial Neural Network(ANN) equalizer is proposed. By considering the characteristics of optical communication networks, the number of nodes in the input layer and hidden layer of the ANN, as well as the number of training samples, are determined. Taking into account the noise in the optical fiber system and the distortion caused by dispersion, the training samples are expanded to enhance the generalization capability of the ANN equalizer. The weights of the ANN equalizer are adaptively adjusted, and small changes in the weight values are utilized to track channel fluctuations, thereby alleviating the problem of weight offset caused by variations in the fiber channel parameters due to changes in environmental conditions. Experimental results show that compared to a non-adaptive ANN, the proposed adaptive ANN has advantages in terms of overall gain, computational complexity, and memory requirements. The model demonstrates strong robustness in optical fiber communication under noisy conditions and has practical value.

Abstract:

Aiming to address the issue of poor new energy accommodation capacity caused by single-objective optimization algorithms in the current coordinated dispatch process of source-grid-load-storage, a multi-objective optimization algorithm is combined to propose an optimized solution method for the coordinated dispatch problem of source-grid-load-storage. With the goals of minimizing dispatch costs and maximizing renewable energy accommodation, a multi-objective optimization function for coordinated dispatch of source-grid-load-storage is defined. Reasonable constraints are set from four aspects: energy components, main grid energy procurement, flexible load response, and energy storage devices. With the assistance of rough set theory, the weight coefficients of each dispatch optimization objective function are determined. An improved whale optimization algorithm with nonlinear weights is introduced to solve the multi-objective optimization function and derive the optimal coordinated dispatch plan. Experimental results show that after applying the dispatch optimization plan generated by the proposed method, the new energy accommodation percentage of the active distribution network reaches 97.25%, significantly enhancing the new energy accommodation capacity of the power system.

Abstract:

In response to the issue of poor authentication effectiveness in traditional encryption and authentication systems, an Internet of Things(IoT)-based 5G power business user identity encryption and authentication system is proposed. In terms of hardware, an encryption chip, a communicator, and an identity recognizer are designed. On the software side, leveraging the information transmission model of the Internet of Things, the identity information of power business users are input to ensure the integrity of the identity information. Using cryptographic Hash function, the Hash values of different data information are calculated to encrypt the user identity information. The authentication of the encrypted user identity is completed through the authentication code generated by the terminal device. Through the above hardware and software designs, the 5G power business user identity encryption and authentication system is completed. In simulation experiments, compared with previous 5G power business user identity encryption and authentication systems, the proposed IoT-based 5G power business user identity encryption and authentication system has an average memory leak value of 32 MB, with better authentication performance and greater application value.

Abstract:

Effective choice of the solution is essential to achieve a real-time, bi-directional(full- duplex) communication of the smart grid. The Power Line Carrier(PLC) technology provides a low-cost solution, which suits China's own national conditions. In this paper, the advantages of OFDM PLC modulation technology are introduced. A PLC module of system model is established through the analysis of the input impedance under the low-voltage power line channel. The high-speed PLC module based on low-voltage Power Line is also designed according to the studies of power line channel. The results show that the design of the PLC module has featured high receiving sensitivity and anti-noise ability.

Abstract:

With the development of Internet applications, users’ demand for bandwidth is soaring sharply. Meanwhile，along with the development of broadband access technology, the endpoint can also adopt multiple network accesses. But due to one-way communication of traditional Transmission Control Protocol(TCP)，the waste of resources will exist. To this end，IETF has specifically proposed Multi-Path TCP(MPTCP) to implement TCP multiplexing，thereby enhancing the efficiency and robustness. This paper gives a review of the IETF’s research on MPTCP，including MPTCP architecture, routing and congestion control, aiming to provide a reference for deeply studying.

Abstract:

Traditional methods and instruments are not able to measure the true Root Mean Square(RMS) of distortion sine wave or non-sine signal accurately. This article introduces a method to measure the true RMS of any high frequency signal by using the true RMS measurement IC，AD536A，designed by AD corporation. The paper analyses the difference between the RMS measured by the average measure method and the true RMS in theory. It explains the disadvantages of current RMS measure method，and presents the design of true RMS measure circuit. The experiment results prove that the proposed method and circuit can measure the true RMS of any high frequency signal accurately.

Abstract:

Terahertz(THz) optoelectronics has promoted the development of the THz generation, transparent control, and detection methods，and hastened many devices in the past decades. Especially, THz metamaterials and metasurfaces will exhibit extraordinary electromagnetic response when the subwavelength scale metal structure is excited by the THz illumination. Therefore, they have been applied to the devices such as wave beam shaper, waveguide, and modulator etc. The THz metamaterials and metasurfaces also show the potential applications in the research fields such as sensors, communications, and radars. In this paper, the works about the spectrum and wavefront modulation with THz metadevices carried out in our group are summarized. The basic theory and corresponding experiment results for different devices are introduced. It is expected these works can pave the avenue of the application of the THz metadevices.

Abstract:

Aiming at the problems in existing underground personnel positioning systems, an assisted positioning method based on pedestrian dead reckoning is proposed. Low-cost Inertial Measurement Unit(IMU) and magnetometer are employed to constitute a stable Attitude Heading Reference System (AHRS). The theory of inertial navigation is utilized, an algorithm for step detection is described, and Zero velocity Update(ZUPT) is adopted for velocity and position estimation to compose a pedestrian dead reckoning system. An experiment is performed in the corridor of a laboratory building to emulate the underground mine road environment. The experimental results demonstrate that the dead reckoning performs well and this method is an effective complement to existing underground positioning by improving the positioning accuracy.

Abstract:

The requirements for micro stress measurement of strain gauge are high precision，high linearity，high stability and high gain. One kind of differential amplifier circuit with excellent performance was designed. Some skillful techniques were adopted to avoid common voltage in the circuit and to reduce the temperature drift. The gain linearity is about 0.01%，and its Common-Mode Rejection Ratio(CMRR) is about 129 dB under work conditions.

Abstract:

According to the requirements of safe, simple and nondestructive radiation effect investigation of semiconductor devices, the method of laser simulation was proposed and greatly promoted. Compared with large-scale facilities, laser simulation has various unique advantages. It helps understand the ionization radiation effect in depth and is an effective low-cost, table-top supplement for the hardness assurance. Its research shows great significance for radiation effect study in both theory and practice. In this paper, the basic principles of the interactions of γ and laser with semiconductor devices are firstly presented. Then the physical basics and characteristics of laser simulation are given, with the research progress review followed. The existing problems of current research are deeply discussed providing with feasible research approaches. In the end, necessary research contents in the future are proposed.

Abstract:

The background requirements of the fuze antenna in terahertz spectrum as well as its advantages and disadvantages are introduced. The working principles and application characteristics of dielectric lens antenna in terahertz frequency are analyzed in order to implement the terahertz fuze antenna. The longitudinal size of H plane horn antenna can be reduced effectively by using fuze antenna formed by an H plane horn with dielectric lens antenna. The terahertz fuze antenna with different beam angles is achieved by focal technology of lens. The feasibility of the technology solution is verified through simulation.

Abstract:

Ultra-wideband(UWB) communication shows its advantages of fast data transfer(100 Mb/s or above) in a relatively short distance(typically below 10 m) with relatively weak power consumption (energy spectrum below -41.3 dBm/MHz). Integrated with Multiple Input Multiple Output(MIMO) technology, channel capacity could be further enhanced. As a critical link in the ultrawideband communication，UWB antenna needs extra efforts in design optimization to boost the performance of the whole system. UWB antenna is defined as the antenna whose bandwidth exceeds 500 MHz or relative bandwidth greater than 20%. This paper takes the most representative Vivaldi antenna as a show case for multi-objective optimization design with statistical methods. The optimized miniaturized antenna(sized130 mm×100 mm) shows a -10 dB bandwidth of 2.4 GHz. The design method provides guidance in common wideband，multi-parameter antenna design.

Abstract:

The design of code tracking loop is a key sector of the realization of noncoherent spectrum spread receiver. In order to realize the code tracking in noncoherent spectrum spread receiver, an energy-normalization digital delay-locked loop was designed, the structure of the loop and the calculating procedure of loop parameters were introduced. The characteristic of noncoherent spectrum spread was analyzed first，and then the key point of the loop design was pointed out. Based on this, the design and realization methods of code loop discriminator, loop filter, early and lag code generator were expatiated. A set of specific loop parameters were introduced as well. Modelsim simulation results and FPGA actual measured data prove the precise code tracking ability of the design.

Abstract:

Radio Frequency IDentification(RFID) series Radio Frequency(RF) card has been applied widely because of its stability，reliability and easy operation features. Aiming at multiple protocols，such as ISO14443 protocol，ISO15693 protocol and Tag-it protocol，this study proposed a new type of circuit design based on Advanced RISC Machine(ARM) for the RFID series RF card reader. The data stream encryption was implemented by using peripheral device in the operation. The system composition，working principle and work flow were introduced. Then，the detailed circuit design of the RF network and encryption hardware were presented，and the test and analysis for the design were performed. The results showed that the circuit could accurately read, write and encrypt various types of card within effective range.

Abstract:

The implementation of TCP/IP protocol stack on TM320DM642 platform could provide technological support for the application of multimedia embedded systems to networks. Both the function of TM320DM642 chip and the hierarchical structure of LWIP(Light Weight Internet Protocol) were analyzed. Network communications for TM320DM642 systems were implemented by the transplantation of LWIP, not by a solution scheme of NDK(Network Developer’s Kit). Testing examples verified the effectiveness of the LWIP transplanted method.

Abstract:

The application of CORDIC(COordinate Rotation DIgital Computing) arithmetic in solving transcendental function has become popular in modern engineering. A brief introduction of CORDIC arithmetic was given in this study. Taking the hyperbolic sine and cosine functions as examples, the method of realizing the arithmetic in FPGA was presented and simulated on ISE(Integrated Software Environment) platform. The result showed this arithmetic was of good precision and instantaneity because of using pipeline. This arithmetic has great practical value in some applications. In addition, a curve of the relationship between the iterative number and the error obtained by the Matlab simulation of the arithmetic can help designers planning the number of iterations for practical applications.

Abstract:

This article introduces a new type of high speed，multi-modulated digital modulator with adjustable center frequency and bit rate features. It can realize the Quadrature Phase Shift Keying(QPSK) and 16QAM(Quadrature Amplitude Modulation) with 80 MHz center frequency and 7.936 5 MHz bandwidth. The general-purpose modulation arithmetic based on software radio，symbol mapping and the realization of pulse shaping filter are discussed. The measuring results demonstrate that the modulation scheme meets the requirements of practicability and general utilization.

Abstract:

The Spatial Light Modulation(SLM) technology has been widely applied to the fields of threshold switch, high speed optical interconnection and optical logic operations, which demands good performance on the real-time and fast optical signal addressing. Compared with Electro-Addressing SLM(EA-SLM), Optically-Addressing SLM(OA-SLM) shows great advantages of fast speed and high resolution by parallel addressing. Nevertheless, how to achieve fast and stable optically addressing is the key point in practice. Based on ZnO thin film as a photoconductive layer, Liquid Crystal OASLM(LC-OASLM) is designed and fabricated; the modulation of the readout light intensity and phase distribution in the two-dimensional space is achieved effectively.

Abstract:

High-speed data acquisition system is an important component in modern radar signal processing. A design of high-speed data acquisition system based on band-pass sampling was presented and applied to the signal processing of wideband receiver. The Virtex Series FPGA was used as the main platform to control the high-speed ADC08D1000 for completing data acquisition, transmission，storage and signal processing. High-speed First Input First Output(FIFOs) were selected as the storage devices to implement data rate conversion. The system realized the software and hardware design，and test results verified the feasibility of the solution.

Abstract:

The corresponding solutions are proposed to tackle with the disadvantages of conventional oilfield Geographic Information System(GIS), including inconvenience of Client/Server(C/S) mode operation and maintenance, being unable to perform real-time online Point of Interest(POI) rendering, being incapable of segmentation and location according to regions, etc. An oilfield information query system of Browser/Serve(B/S) framework based on AJAX+JSON+HTML5 is designed and implemented. Experimental results show that the POI real-time rendering and regional segmentation improve on their interactivities, and the experiences of users are enriched, which meets the actual requirements of oilfield development. This work has paved the way for the development of diversified network services.

Abstract:

A detector can achieve quick response when it is much smaller than the wavelength of the source signal in THz wave band at the expense of signal coupling capability．Therefore, an antenna is applied to collect signals in order to enhance the signal coupling capability of the detector．The properties of antenna determine the frequency response band，the sensitivity and other parameters of the detector directly. A planar-integrated antenna is adopted for signal acquisition in the Nb5N6 microbolometer detector, which is fabricated by lithography，lift-off and other processes of micro-fabrication. The Nb5N6 microbolometer is placed in the center of the planar antenna. Aiming for the center frequency of 0.32 THz, a special capacitive coupling design is proposed to improve the signal coupling capability．

Abstract:

A double gate setting with priority of Doppler velocity and the Extended Kalman Filter(EKF) based Multiple Hypothesis Tracking(MHT) algorithm are proposed in order to realize Multiple Targets Tracking(MTT) in High Frequency(HF) ground-wave radar, and to effectively improve the performance of MTT by using the Doppler measurement. In the EKF based MHT, parameters obtained in the EKF are adopted directly to calculate the probability of each hypothesis. A simulation scene is built, and the EKF based MHT algorithm is compared with the one which assumes that the Doppler measurement is independent from the radius measurement. Simulation results show that the double gate setting helps induce number of clutter, and the EKF-based MHT algorithm is better than the other one under dense environments of HF ground-wave radar with stronger track-catching and false-alarm-filtering ability and higher efficiency.

Abstract:

The single-channel blind separation of GMSK(Gaussian Minimum Shift Keying) mixing signals is researched. The GMSK mixing signals can not be separated by the Per-Survivor Processing (PSP) algorithm directly, therefore, linear approximation processing of the GMSK signal is considered, which enables GMSK signal to be separated by the PSP algorithm. This algorithm separates the GMSK mixing signals by maximum likelihood estimation in the joint space of the symbol sequential and the channel parameters, reserves the best path and outputs the symbol pairs to get the separated signals. Simulation results show that the bit error rate performance produced by the PSP algorithm on separating the GMSK mixing signals is slightly better than that produced by the particle filtering algorithm; and the complexity of the proposed PSP algorithm is much smaller.

Abstract:

A new usage of Hough Transform is introduced in this paper.Firstly,the position and scope of the license plate is located and the image that contains the license plate is picked up.Then, a two-stage Hough transform algorithm is applied to the image to cal

Abstract:

A forward secure strong proxy signature scheme is proposed on the basis of the proxy signature schemes and forward secure schemes.The security of the proposed scheme relies on the difficulty of solving discrete logarithm problems and the difficulty of com

Abstract:

Based on three generally accepted basic hypotheses, the definition of environmental factor and restricting conditions of constant failure mechanism are discussed.The research status and common study methods of environmental factor are reviewed. Finally, a

Abstract:

For completing the scheme of hard target smart fuze, several factors influencing the outputting acceleration of the high-G accelerometer such as target material, impact angle, impact velocity, the fixed position of accelerometer, carry plane etc., are put

Abstract:

Blind source separation (BSS) is a recently developed methodology used to separate unknown source signals from their mixtures. It has been applied to many fields widely and effectively. The theory and two types of implementation methods-independent compon