压制器的试验研究

本文重点分析研究了不同形式压制器线速度对生产率、剥净率、落粒率、破碎率的影响。利用图表法在给定剥净率时求出剥皮辊的转速及压制器的线速度和剥皮辊的生产率。在此试验的基础上制定出该项试验剥皮辊和压制器的最佳运动规范。

Fast-Lock Low-Jitter PLL with a Simple Phase-Frequency Detector

A fast-locking, low-jitter, phase-locked loop （PLL） with a simple phase-frequency detector is proposed. The phase-frequency detector is composed of only two XOR gates. It simultaneously achieves low jitter and short locking time. The voltage-controlled oscillator within the PLL consists of four-stage ring oscillators which are coupled to each other and oscillate with the same frequency and a phase shift of 45. The PLL is fabricated in 0. 1Stem CMOS technology. The measured phase noise of the PLL output at 500kHz offset from the 5GHz center frequency is - 102.6dBc/Hz. The circuit exhibits a capture range of 280MHz and a low RMS jitter of 2.06ps. The power dissipation excluding the output buffers is only 21.6roW at a 1.8V supply.

采用P—80编码钟的三方位深层模拟地震仪的研制

在对比分析国内外同类仪器基础上,长春地质学院、重庆地质仪器厂联合研制成功了深层模拟地震仪。本文着重阐述了仪器试制中解决的难点,并论述了该仪器的特点。 一、仪器各部份的研制 整个系统分为野外接收台站和基地回放站。野外接收台站包括三维检波器、调制器、磁带机等三箱。基地回放站包括磁带机、解调器、纸记录器等三箱。 1.

Design of voltage-controlled dynamic band-pass filter based on VCA810

In order to filter signal effectively according to selective center frequency, a voltage-controlled dynamic band-pass filter with gain compensation was designed based on voltage-controlled gain wideband amplifier VCA810. The transfer function of the filter was analyzed and gain compensation voltages were given through tests; besides, a system was designed, including the gain compensation circuit and the control voltage circuit, etc. Center frequency will change from 1 kHz to 20 kHz according to control voltage on condition that bandwidth of the filter remains constant. The designed system has the advantages of simple structure, low noise, stable performance and convenient adjustment.

A Compact Ka-Band PHEMT MMIC Voltage Controlled Oscillator

A compact Ka-band monolithic microwave integrated circuit(MMIC) voltage controlled oscillator (VCO) with wide tuning range and high output power,which is based on GaAs PHEMT process,is presented.A method is introduced to reduce the chip size and to increase the bandwidth of operation.The procedure to design a MMIC VCO is also described here.The measured oscillating frequency of the MMIC VCO is 36±1.2GHz and the output power is 10±1dBm.The fabricated MMIC chip size is 1.3mm×1.0mm.

Analysis of input harmonic current mitigating performance in dual output phase-shift distribution transformer

A novel dual output phase-shift distribution transformer （ DOPSDT ） is proposed based on the electromagnetic filtering theory. First, its structural characteristics, winding connection mode and turn number ratio for special phase shifting are investigated. Secondly, the balance formulation of harmonic magneto-motive forces is derived and the electromagnetic filtering principle of the DOPSDT is introduced. The harmonic mitigating performance under different nonlinear load conditions are also analyzed using the field-circuit coupled method, The analysis results show that the DOPSDT can mitigate the primary current distortion even under severe nonlinear load conditions. By applying the zero sequence flux cancellation and phase-shift techniques at their secondary windings, the DOPSDT can significantly reduce the 3rd, 5th, 7th, 9th, 15th, 17th and 19th harmonics within its secondary windings.

A Novel Polysilicon and Oxide Sandwich Deep Trench with Field Limiting Ring for RF Power Transistors

A vertical sandwich deep trench with a field limiting ring is proposed to improve the breakdown voltage of power devices and high voltage devices.Simulation result shows that nearly 100% breakdown voltage of the plane junction can be realized.

A 2GHz Low Power Differentially Tuned CMOS Monolithic LC-VCO

A 2GHz differentially tuned CMOS monolithic LC-VCO is designed and fabricated in a 0.18μm CMOS process. The VCO has a 16.15% tuning range （from 1. 8998 to 2. 2335GHz） through a combination of analog and digital tuning techniques （4-bit binary switch-capacitor array）. The measured phase noise is - 118.17dBc/Hz at a 1MHz offset from a 2. 158GHz carrier. With the presented improved switch,the phase noise varies no more than 3dB at different digital control bits. The phase noise changes only by about 2dB in the tuning range because of the pn-junctions as the varactors. The VCO draws a current of about 2. lmA from a 1.8V power supply and works normally with a 1.5V power supply.

Active Vibration Control and Stability Analysis of Cantilever Plate

Active vibration control and stability analysis of cantilever plate are discussed. Based on the analysis of characteristic equation of the closed loop control system, it is shown that such an active control may increase damping properties of the system, meanwhile it may result in instability of the system. It is stable when the feedback only occurs between the collocated sensors and actuators, but it may be unstable when there exists the feedback between sensors and actuators, which mainly depends on the property of the gain matrix of feedback. If the gain matrix is symmetric and definitely positive, the system is stable.

Fabrication and Simulation of an AlGaAs/GaAs Ultra-Thin Base NDR HBT

A novel mesa ultra-thin base AlGaAs/GaAs HBT is designed and fabricated with wet chemical selective etch technique and monitor electrode technique. It has a particular and obvious voltage-controlled NDR whose PVCR is larger than 120. By use of device simulation,the cause of NDR is that increasing collector voltage makes the ultrathin base reach through and the device transforms from a bipolar state to a bulk barrier state. In addition, the simulated cutoff frequency is about 60-80GHz.

Design and Fabrication of a High-Voltage nMOS Device

High-voltage nMOS devices are fabricated successfully and the key technology parameters of the process are optimized by TCAD software. Experiment results show that the device＇s breakdown voltage is 114V, the threshold voltage and maximum driven ability are 1.02V and 7.5mA（W/L = 50）, respectively. Experimental results and simulation ones are compared carefully and a way to improve the breakdown performance is proposed.

Application of adaptive fuzzy control technology to pressure control of a pressurizer

A pressurizer is one of important equipment in a pressurized water reactor plant. It is used to maintain the pressure of primary coolant within allowed range because the sharp change of coolant pressure affects the security of reactor, therefor, the study of pressurizer’s pressure control methods is very important. In this paper, an adaptive fuzzy controller is presented for pressure control of a presurizer in a nuclear power plant. The controller can on-line tune fuzzy control rules and parameters by self-learning in the actual control process, which possesses the way of thinking like human to make a decision. The simulation results for a pressurized water reactor plant show that the adaptive fuzzy controller has optimum and intelligent characteristics, which prove the controller is effective.

Pressure-tracking control of a novel electro-hydraulic braking system considering friction compensation

This work presents an integrated pressure-tracking controller for a novel electro-hydraulic brake(EHB) system considering friction and hydraulic disturbances. To this end, a mathematical model of an EHB system, consisting of actuator and hydraulic sub-systems, is derived for describing the fundamental dynamics of the system and designing the controller. Due to sensor inaccuracy and measurement noise, a Kalman filter is constructed to estimate push rod stroke for generating desired master cylinder pressure. To improve pressure-tracking accuracy, a linear friction model is generated by linearizing the nonlinear Tustin friction model, and the unmodeled friction disturbances are assumed unknown but bounded. A sliding mode controller is designed for compensating friction disturbances, and the stability of the controller is investigated using the Lyapunov method. The performance of the proposed integrated controller is evaluated with a hardware-in-the-loop(HIL) test platform equipped with the EHB prototype. The test results demonstrate that the EHB system with the proposed integrated controller not only achieves good pressure-tracking performance, but also maintains robustness to friction disturbances.

DAMAGES AND FAILURES OF SMART STRUCTURES

According to some observed dama ge phenomena in the smart structure systems, the issues related to the damage and failures of smart structures are addressed in this paper. A few possible damage patterns and the definition of the failure of the smart structures are given. It is pointed out that more attentions should be paid to the functional failures o f smart structures. The effects on the control the static deformation due to par tial debonding of PZT actuators are analyzed by the finite element method. Preli minary numerical results show that partial debonding of PZT actuators may have a p preciate reduction on their actuating ability thus reducing the control ability and accuracy of the smart structures.

Precision Tension Control System Using Magnetic Particle Clutch

The control of the stability of the filament tension is one of the crucial techniques ensuring the component quality of the composite materials. The open-loop tension control system, with industrial control computer as the core, magnetic particle clutch as the actuator, equipped with compensation technique is researched and manufactured. It can assure the tension control stability of the yarn in filament winding process and increase the control precision of the whole system.

Inhibition characteristics of circulating current in parallel inverter driving system of mine hoist

This research investigated the outputting circulation current inhibition characteristic which are controlled by the instantaneous feedback voltage in inverter parallel driving of the mine hoist. We established a transfer function of the parallel inverters controlled by the close-loop adjustment of instantaneous voltage feedback. The influence of the parameters of the close-loop feedback circuit to the inhibition effects to the outputting circulation current is observed. After analyzing the circulating current inhibition characteristics, the proportion integration （PI） controller is introduced into the close-loop adjustment by instantaneous voltage feedback. The characteristics equation is gained to determine the PI parameters by drawing the Bode plots. The inhibition effects of the proposed controller are examined by the established simulation model of parallel inverter system. The harmonic distortion rate at the outputting voltage frequency value of 4, 10, 20, 41 and 50 Hz, are all lower than 2.32 % by the instantaneous outputting voltage feedback.

Novel consistency control strategy for jet dispensing

A new consistency control method for jet dispensing is proposed. First, the working parameters, namely, viscosity, supply pressure and supply time, are experimentally investigated. Then, the glue viscosity is approximated by a polynomial model using the least square method. Based on this model and temperatme control implemented using the Dahlin principle, the viscosity of the glue can be maintained at a constant value. Then, the viscosity model of the glue is applied to deriving the droplet mass as the nominal model of the temperature controller. The robustness of the temperature controller is analyzed by applying the small gain theory. The glue supply pressure controller is designed using the consistency control strategy, and the robustness is analyzed. Finall）, simulations and experiments are conducted using a jet dispensing control system. The results show that the proposed control strategy can significantly improve the droplet consistency.

Research on CMOS Mm-Wave Circuits and Systems for Wireless Communications

This paper lenges in the design of discusses some chal- millimeter-wave （mln- wave） circuits and systems for 5th generation （5G） wireless systems in CMOS process. The properties of some passive and active devices such as inductors, capacitors, transmission lines, translbrmers and transistors in mm-wave frequency band are discussed. Self-healing technique dealing with PVT variation, res- onant mode switching technique to enhance frequency tuning range of voltage controlled oscillator （VCO） and dual mode technique for power amplifier （PA） efficiency enhancement are introduced. At last, A fully-integrated 60 GHz 5 Gb/s QPSK transceiver with the transmit/receive （T/R） switch in 65nm CMOS process is introduced. The measured error vector magnitude （EVM） of the TX is -21.9 dB while the bit error rate （BER） of the RX with a -52 dBm sine-wave input is below 8e-7 when transmitting/receiving 5 Gb/s data. The transceiver is powered by 1.0 V and 1.2 V supply （except the phase-frequency detector and charge-pump in the frequency synthesizer which are powered by 2.5 V supply） and con- sumes 135 mW in TX mode and 176 mW in RX mode.

2.7-4.0 GHz PLL with dual-mode auto frequency calibration for navigation system on chip

A 2.7-4.0 GHz dual-mode auto frequency calibration(AFC) fast locking PLL was designed for navigation system on chip(SoC). The SoC was composed of one radio frequency(RF) receiver, one baseband and several system control parts. In the proposed AFC block, both analog and digital modes were designed to complete the AFC process. In analog mode, the analog part sampled and detected the charge pump output tuning voltage, which would give the indicator to digital part to adjust the voltage control oscillator(VCO) capacitor bank. In digital mode, the digital part counted the phase lock loop(PLL) divided clock to judge whether VCO frequency was fast or slow. The analog and digital modes completed the auto frequency calibration function independently by internal switch. By designing a special switching algorithm, the switch of the digital and analog mode could be realized anytime during the lock and unlock detecting process for faster and more stable locking. This chip is fabricated in 0.13 μm RF complementary metal oxide semiconductor(CMOS) process, and the VCO supports the frequency range from 2.7 to 4.0 GHz. Tested 3.96 GHz frequency phase noise is -90 d Bc/Hz@100 k Hz frequency offset and -120 d Bc/Hz@1 MHz frequency offset. By using the analog mode in lock detection and digital mode in unlock detection, tested AFC time is less than 9 μs and the total PLL lock time is less than 19 μs. The SoC acquisition and tracking sensitivity are about-142 d Bm and-155 d Bm, respectively. The area of the proposed PLL is 0.35 mm^2 and the total SoC area is about 9.6 mm^2.