探地雷达收发开关系统的设计

 针对当前探地雷达中双天线存在严重耦合影响了信号检测的问题,开发了一种高速的开关系统.通过ADS电路仿真和参数优化,利用PIN管芯制作了一种串/并联结构的宽带高隔离度微带单刀双掷开关,设计了开关的电源电路和驱动电路.经过实验测量表明该开关系统达到了技术指标要求,能满足探地雷达的要求.     

单刀双掷开关在自动增益控制电路中的应用

自动增益控制电路(AGC)是微波接收机中常用的一种电路。为了提高器件使用效率,优化端口驻波匹配,可以使用单刀双掷开关来实现AGC电路。单刀双掷开关采用PIN二极管制作,其插入损耗小、隔离度较高、并且端口驻波较好。该开关采用串并联电路方式,并利用Ansoft公司的Serenade软件对其进行仿真优化,电路基板使用Rogers的RT5880板材。经过实际测试,该AGC电路的工作频率为9.5～10.5GHz,正常支路插损小于4dB,带内平坦度0.5dB,输入输出驻波比小于1.6。     

多阻带螺旋滤波器设计

采用微带螺旋结构设计了一个多阻带螺旋滤波器。设计中选择了合适的等效电路模型，对微带电路的结构进行了仿真和优化。并根据优化结果制作并测试了多阻带螺旋滤波器。多阻带滤波器把特定频率的信号变弱，从而创建特定频谱，可应用于RFID标签的制作。     

基于MEMS开关双频微带缝隙天线的设计

本文设计了一种基于MEMS开关的快速切换频率的双频微带缝隙天线.通过MEMS开关的通断来改变缝隙的尺寸,从而改变电流分布,实现天线谐振频率在2.4GHz和5.8GHz之间的快速切换.分析了MEMS开关状态与天线谐振频率之间的关系.仿真结果显示,当开关断开时,微带缝隙天线的频率为2.4GHz,回波损耗达到-27dB;当开关闭合时,微带天线工作频率切换到5.8 GHz,回波损耗达到-23dB,并通过实测数据验证了仿真结果.     

结冰探测信号调理电路设计与试验研究

介绍了基于光强检测的结冰探测电路的设计方法与试验结果。选择了大面积PIN光电管C30809E,设计、制作光电转换电路和放大滤波电路,做好屏蔽和降噪处理,提高了信噪比,实现了对微弱光电流信号的检测。实测毛冰、明冰对808nm红外激光的反射强度,实现对3mm以上冰层的可靠检测。     

用于卫星通信的S波段宽带圆极化微带天线阵设计方法

提供了一种用于卫星通信的S波段宽带圆极化微带天线阵的设计方法,采用口径耦合馈电,利用连续相位旋转法实现圆极化工作,并增加空气基板展宽其工作带宽。在此设计基础上制作了天线阵实物,实测VSWR1.5的阻抗带宽为23.8%,最大增益为14.5dB。     

毫微秒脉冲相关器应用的GaAs单片超高速模拟开关IC

介绍一种ＧａＡｓ单片超高速模拟开关ＩＣ的设计和制备。电路设计采用了独特的开关管导通时栅－源电压跟随和开关管关断时栅－源电压箝位的电路，使开关获得良好的线性和３ｎｓ的开启和关断超高速特性，满足了毫微秒脉冲相关信号的处理要求。     

一种重力开关的设计

目的 研究一种实用于存储测试装置在测试飞行体的飞体参数时；方便其上电的开关。方法 利用存测装置相对于重力方向的变化来设计。结果与结论 制作了一种简单小巧、上电方便的开关。     

双向型球式体积管检测开关变动不影响其体积值的探讨

体积管的标准体积值是由其检测开关的位置决定的、依据双向型体积管的原理，利用其对称性和补偿性的特点，可以消除检测开关因维修变动对双向型体积管标准体积值的影响，解决了双向型体积管在检定周期内因检测开关故障需要检修时，无需重新清洗、检定的问题。文章在理论上进行论述，并通过试验给予了验证。     

新型宽频带微带贴片天线的设计

 提出了一种新颖的展宽三角形微带贴片天线工作频带的设计方法．通过在三角形微带贴片侧边附近加载与之平行的缝隙来实现双频工作,并添加一对平行于底边的缝隙使两个频点靠近,利用仿真软件进行优化,有效地展宽了贴片天线的频带．制作了实际的贴片天线,结果表明所设计天线的工作带宽(VSWR<2)是普通三角形微带天线的4.46倍,且天线尺寸与同频率的常规贴片天线相比缩小了9.3%．测量结果与仿真结果吻合,证明了所提方法的有效性．     

Frequency spurious aversion by minimal reverse bias selection of a high-speed optically triggered sampling circuit based on a positive-intrinsic-negative photodiode

In this paper we present a procedure for the selection of the minimal dc reverse bias voltage of a high-speed optically triggered sampling circuit. The optically triggered sampling circuit is based on a PIN photodiode. A set of expressions that includes the optical power dependence of the current passing through the PIN photodiode is derived. Theoretical results of the procedure are experimentally verified with practical measurements obtained from a 3 giga samples per second (GS/s) and a 20 GS/s sampling circuit implemented with commercial PIN photodiodes. Reductions in the signal-to-noise and distortion ratio of 37.28 and 6.9?dBs, as well as increments in the spurious free dynamic range of 31 and 19?dBs in the sampled signals, are respectively averted by the selection of the minimal reverse bias.     

PIN结构自扫描光电二极管列阵的研究

通过对再充电采样方式的自扫描光电二极管列阵（ＳＳＰＡ）工作原理分析，对列阵中光电二极管工作模式进行较深入的探讨，指出影响其性能的主要因素。提出了用ＰＩＮ结构代替常用的ＰＮ结结构的光电二极管组成ＳＳＰＡ。经过ＰＩＮ结构和ＭＯＳ电路兼容工艺方案的分析及实验，测试结果表明ＰＩＮ结构有利于改进ＳＳＰＡ的性能，是研究高性能ＳＳＰＡ的新结构。     

Tunable coupled-ring-resonator of thermally actuated optical switch array

In this research, we design tunable micro-ring resonators and propose the employment of an integrated control circuit to compensate for the fabrication error, and tune as well as lock the wavelength in a thermal-actuated ring-type optical switch through an amplitude modulation scheme. Additional functionalities can also be added in this circuit by tailoring externally the roundtrip loss or coupling constants of the ring. The design concept can be easily scaled up for a large array optical switch system without much change to the terminal numbers thanks to the three-dimensional hierarchy of the high gray-scale control circuit design, which effectively reduces the terminal numbers to the cubic root of the total control unit numbers. The integrated circuit has been designed, simulated, as well as fabricated, and demonstrated a decent performance with free spectral range (FSR) equal to 1.5 nm at 1532 nm and very accurate wavelength modulation to 0.3 nm within 0.01 nm fluctuation for a thermal actuated ring type optical switch.     

Analysis and implementation of an active snubber dc/dc converter with series?parallel connection in primary and secondary sides

An active snubber dc/dc converter to achieve zero voltage switching (ZVS) on power switch is presented. In the proposed converter, the primary windings of two transformers are connected in series so that the primary currents of the two transformers are equal. The secondary sides of the isolated zeta converters are connected in the parallel to share the load current and reduce the current stresses on the secondary windings of the two transformers. A boost type of active snubber is connected in parallel with the main switch to recycle the energy stored in transformer leakage and magnetizing inductors and to limit voltage stress of the main switch. During the transition interval between the active switch and the auxiliary switch, the resonance based on the resonant inductor and the output capacitor of the power switch will allow the switch to turn on at ZVS. The principle of operation, steady-state analysis and design consideration of the proposed converter are provided. Finally, experimental results for a 360 W (12 V/30 A) prototype circuit with 150 kHz switching frequency were given to demonstrate the circuit performance and verify the feasibility of the proposed converter.     

Design of a bistable switch to control cellular uptake

Bistable switches are widely used in synthetic biology to trigger cellular functions in response to environmental signals. All bistable switches developed so far, however, control the expression of target genes without access to other layers of the cellular machinery. Here, we propose a bistable switch to control the rate at which cells take up a metabolite from the environment. An uptake switch provides a new interface to command metabolic activity from the extracellular space and has great potential as a building block in more complex circuits that coordinate pathway activity across cell cultures, allocate metabolic tasks among different strains or require cell-to-cell communication with metabolic signals. Inspired by uptake systems found in nature, we propose to couple metabolite import and utilization with a genetic circuit under feedback regulation. Using mathematical models and analysis, we determined the circuit architectures that produce bistability and obtained their design space for bistability in terms of experimentally tuneable parameters. We found an activation–repression architecture to be the most robust switch because it displays bistability for the largest range of design parameters and requires little fine-tuning of the promoters'' response curves. Our analytic results are based on on–off approximations of promoter activity and are in excellent qualitative agreement with simulations of more realistic models. With further analysis and simulation, we established conditions to maximize the parameter design space and to produce bimodal phenotypes via hysteresis and cell-to-cell variability. Our results highlight how mathematical analysis can drive the discovery of new circuits for synthetic biology, as the proposed circuit has all the hallmarks of a toggle switch and stands as a promising design to control metabolic phenotypes across cell cultures.     

一种电子雷管发火电路开关驱动的研究

介绍了一种电子雷管点火头发火电压检测仪中的发火电路开关的设计与优化。试验表明使用NMOS或CMOS反相器驱动电容放电式火工品的发火电路开关,电容放电式发火电路开关的导通过程时间1μs,开关导通过程中的电容能量损失〈0．8％。     

A Novel Design of Mechanical Switch for the High Overload Environment

The internal structure of the inertial measurement unit (IMU) in active state is easily damaged in the high overload environment. So that the IMU is usually required to be powered within the disappearance of the high overload. In this paper, a mechanical switch is designed to enable the IMU based on the analysis of the impact of high overload on the power-supply circuit. In which, parameters of mechanical switch are determined through theoretical calculation and data analysis. The innovation of the proposed structure lies in that the mechanical switch is triggered through the high overload process and could provide a delay signal for the circuit. After all, the proposed switch is tested through mechanical simulation, impact test and practical test. The experimental results show that the designed mechanical switch can effectively and reliably provide the delay for the circuit and guarantee operation of the IMU under high overload.     

GaAs霍尔开关集成电路的研制

成功地设计并制造出GaAsMESFET霍尔开关集成电路。该电路采用了方形霍尔元件，绝对灵敏度为704mV/T；信号处理电路由差分放大电路和触发电路组成，触发电路结构类似于SCFL的D触发器。结果表明，开关性能良好，工作点合理，达到设计要求。实验结果还表明，霍尔元件和放大电路可构成灵敏度很高的霍尔线性集成电路。     

Electrorheological properties and creep behavior of polyindole/poly(vinyl acetate) composite suspensions

In this study, electrorheological (ER) properties of polyindole (PIN) and polyindole/poly (vinyl acetate), (PIN/PVAc) conducting composites having different compositions were investigated. Conductivities and dielectric properties of these composites were determined. The particle sizes of the composites were determined by dynamic light scattering method. Suspensions of PIN and PIN/PVAc composites were prepared in silicone oil, at several concentrations (c = 5–25%, m/m) and their sedimentation stabilities were determined. Then the effects of dispersed particle concentration, shear rate, electric field strength, frequency, and temperature onto ER activities of suspensions were investigated. The flow times of these suspensions at various dc electric field strengths were measured. Further, creep tests were applied to the composite suspensions and a reversible viscoelastic deformation was observed.