电流模集成电抗元件与频率变换电路的设计

为了拓宽电流模单元电路结构在低压低功耗射频集成电路中的应用,研究把第二代电流传输器用作电抗器件和频率变换电路。以第二代电流传输器为核心,辅助予外围电路,构造从输入到输出端口不同性质传输阻抗的有源电容倍增器和有源电感,并且基于第二代电流传输器组合结构差异的分析,设计了集成频率变换电路。从理论上,推出有源电容倍增器和有源电感结构的合理性。仿真集成频率变换电路,结果袁明对40MHz以下正弦波倍频功能正确,且以100kHz正弦波为调制信号和以10MHz的正弦波为载波获得了双边带调幅信号。这为射频集成电路设计提供了新的思路。     

新型声光通信激光多普勒信号的鉴频电路

根据激光多普勒测振技术进行声光通信的工作原理,设计一种新型、小型激光多普勒测振信号鉴频电路。该电路根据外差探测原理,本地振荡器输出信号与探测信号混频得到一路信号,经90°移相后的本地振荡器输出信号再与探测信号混频得到另一路信号,利用这两路信号得到了多普勒频移量和声源振动的频率。利用扬声器激发的水面模拟振源进行实验,表明该电路可有效测量的振动频率范围为300 Hz~10 kHz,证明可用于水下光声通信。     

Design of adaptive dead-time control circuit for resonant half-bridge driver

To decrease the switching loss and the dead-time effect of resonant half-bridge inverter, a novel adaptive dead-time control circuit of resonant half-bridge driver Integrated Circuit (IC) is presented. Without increasing the pin number of IC, this circuit takes a novel strategy to adaptively regulate dead time to a temperate range between high and low thresholds. The high and low thresholds are adaptive to the fall time of output signal in a half-bridge clock cycle. The IC of the designed circuit is suitable for high-voltage applications. The dead-time regulation range of this circuit achieves 0–3.5?µs. The range of temperate dead-time state is 300?ns. The failure signal of this circuit can protect the IC and peripheral power devices by regulating operation in three clock cycles. Both simulation and measurement of the proposed circuit in a half-bridge driver IC with an operating frequency at 50?kHz are presented based on the 0.5?µm 700?V BCD process. The results of simulation and measurement show that the presented circuits’ performance is perfect.     

MOS triangle-to-sine wave convertor based on subthreshold operation

A novel MOS triangle-to-sine wave convertor (TSC) is proposed. The novel circuit is based on the exponential characteristics of MOS devices operated in the subthreshold region. The circuit with a total harmonic distortion of 0.21% and bandwidth of 100 kHz has been demonstrated by PSPICE simulation and experiments.<>     

A zero-voltage switched, three-phase isolated PWM buck rectifier

A novel three-phase, single-stage, isolated PWM rectifier is proposed, which is capable of achieving unity power factor, and low harmonic distortion of input currents, and at the same time realizing zero-voltage switching for all power semiconductor devices. Operation of the proposed circuit is thoroughly analyzed. Design equations and trade-offs are provided. The performance of the proposed circuit is demonstrated through a 2 kW, 100 kHz, digital signal processor controlled prototype. The conversion efficiency is around 93%     

Novel zero-voltage-transition current-fed full-bridge PWM converterfor single-stage power factor correction

A novel zero-voltage-transition (ZVT) current-fed full-bridge pulsewidth modulation (PWM) power converter for single-stage power factor correction (PFC) is presented to improve the performance of the previously presented ZVT converter. A simple auxiliary circuit which includes only one active switch provides a zero-voltage-switching (ZVS) condition to all semiconductor devices (two active switches are required for the previous ZVT converter). This leads to reduced cost and a simplified control circuit compared to the previous ZVT converter. The ZVS is achieved for wide line and load ranges with minimum device voltage and current stresses. Operation principle, control strategy and features of the proposed power converter are presented and verified by the experimental results from a 1.5 kW 100 kHz laboratory prototype     

A 12-bit sigma-delta analog-to-digital converter with a 15-MHz clock rate

A sigma-delta analog-to-digital converter that achieves 12-bit integral and differential linearity and nearly 13-bit resolution without trimming is described. The baseband width is 120 kHz with a first filter pole at 60 kHz, the clock frequency is 15 MHz, and only one 5-V power supply is needed. The circuit was realized in a p-well CMOS technology with 3-/spl mu/m minimum feature size. Compared with previous sigma-delta modulators, the input signal frequency and clock rate limit have been increased by one order of magnitude. To achieve this increase, a novel integrator concept was developed using bidirectional current sources. The circuit is fully self-contained, requiring only a 15-MHz crystal and one blocking capacitor as external elements. This converter was developed as the analog front end of a digital echo cancellation circuit for an integrated services digital network.     

基于兰姆波压电谐振器的高频低相噪MEMS振荡器仿真研究

发达的现代通信设备对时钟源器件提出了更高的要求,在保障频率信号稳定的同时还需要器件具备可集成、微型化等特点,微机电系统(MEMS)振荡器因其具备这些优势,已逐渐替代传统振荡器,成为电子设备中信号源的常用元器件。该文设计了一种MEMS振荡器并对其进行仿真测试,该振荡器的核心选频器件由Lamb波压电谐振器组成,在应用于振荡电路前,对设计的MEMS谐振器进行了仿真测试,并提出两种优化其寄生模态的方法,所得谐振器的品质因数(Q)为1 357.5,串联谐振频率为70.384 MHz。将优化后谐振器应用于振荡电路后,对振荡器输出信号和相位噪声进行测试,结果表明,MEMS振荡器的输出载波频率为70.58 MHz,相位噪声为-64.299 dBc/Hz@1 Hz及-144.209 dBc/Hz@10 kHz。     

基于电流镜的同步积分模式双色读出结构设计

文章对N+PPN结构的MW／LW双色红外焦平面信号电流同步积分的工作模式，提出了一种双色读出电路输入级的新结构，即在栅调制注入输入级的基础上加以设计改进，采用电流镜对一个独立波段(LW)的信号电流进行两路精确复制，分别用于此波段的信号电流积分、与混合波段信号电流的相减，解决了探测器输出端混合波段信号电流的分离问题，达到了两个波段信号电流同步独立积分的目的。本文就双色电路的输入级结构和工作原理进行了详细的阐述，电路模拟验证的结果表明该电路适用于信号电流大于10nA的双色器件(MW／LW,MW1／MW2，LW1／LW2双色器件)，有较高的精确度(误差<2％)和良好的性能。     

基于脉冲信号（方波）的正弦信号产生电路的设计

正弦信号广泛应用于电路系统测试与控制中,有多种电路设计方案可产生正弦信号。本文采用基于脉冲信号（方波）的正弦信号产生电路方案进行电路设计。该电路可产生脉冲信号（方波）频率（9kHz）奇数倍的固定频率的正弦信号Ⅰ、Ⅲ（基波Ⅰ：9kHz,三次谐波Ⅲ：27kHz,┅,）,且信号波形质量较好。测试表明：产生的正弦信号的频率与幅值与脉冲信号傅里叶级数展开结果基本相符合。设计过程中采用了Multisim 11.0仿真。本文对正弦信号产生电路的设计有一定的参考价值。     

Novel CCD-based pH imaging sensor

We propose and demonstrate a novel pH imaging sensor based on the Charge Coupled Device (CCD) technology. This device consists of pH sensing parts, which sense pH value and transform a pH value to electric charges, and conventional CCD parts, which transfer the electric charges to read out circuit. A thin Si₃N₄ film which acts as the hydrogen ion-sensitive membrane was used in the pH sensing film. The prototype devices were fabricated and was confirmed the device operation using pH equivalent voltages. It was found that the output signal from the imaging sensor was lineally changed from pH 0 to 14 and successfully observed a pH image on a black and white TV monitor     

High-accuracy resolver-to-linear signal converter

A high-accuracy resolver-to-linear signal converter for the measurement of angular displacement is proposed in this paper. The proposed converter comprises two sections: a demodulator and linear shaper. In the first section, the demodulator makes use of the sample-and-hold circuit (SHC) to sample the peak amplitude of the resolver signal. The control signal of the SHC is provided from the resolver signals instead of the excitation signal used in traditional approaches. The proposed demodulator requires no analogue multiplier and low-pass filter. Therefore, the fast response time of the proposed demodulator is achieved. In the second section, the linear shaper consists of the inverse-sine function scheme together with a switched-gain amplifier to produce the linear signal proportional to the shaft angle. The hyperbolic tangent characteristic of the operational transconductance amplifier is utilised to realise the inverse-sine function scheme. The proposed technique requires one phase of the resolver signal to obtain the linear signal. Therefore, the position error caused by amplitude imbalance between the two resolver signals is avoided. The performances of the proposed converter are discussed in detail and demonstrated by an experimental implementation using commercial devices. The experimental results show that the maximum relative error and response time for the excitation frequency of 3 kHz are measured as 0.06% and 0.11 ms, respectively.     

State-plane analysis of a constant-frequency clamped-modeparallel-resonant converter

A novel clamped-mode parallel-resonant converter which operates at a constant frequency and provides a wide output voltage regulation range is proposed and analyzed. Employing graphical state-plane techniques, five circuit operating modes are identified and their mode boundaries defined. Regions for natural and forced commutation of power devices are specified. The DC control-to-output characteristics are derived to facilitate converter design. The predicted operating modes are experimentally verified using a 105 kHz prototype circuit     

High-accuracy current sensing circuit with current compensation technique for buck–boost converter

A novel on-chip current sensing circuit with current compensation technique suitable for buck–boost converter is presented in this article. The proposed technique can sense the full-range inductor current with high accuracy and high speed. It is mainly based on matched current mirror and does not require a large proportion of aspect ratio between the powerFET and the senseFET, thus it reduces the complexity of circuit design and the layout mismatch issue without decreasing the power efficiency. The circuit is fabricated with TSMC 0.25 µm 2P5M mixed-signal process. Simulation results show that the buck-boost converter can be operated at 200 kHz to 4 MHz switching frequency with an input voltage from 2.8 to 4.7 V. The output voltage is 3.6 V, and the maximum accuracy for both high and low side sensing current reaches 99% within the load current ranging from 200 to 600 mA.     

激光扫描仪接收系统的峰值保持电路设计

针对激光扫描仪接收系统对信号窄脉宽、高重频、大带宽的设计要求,提出2种保持时间可调的峰值保持电路的设计方法。一种利用跨导型放大电路实现峰值保持,单稳态触发器实现保持时间控制;一种利用FastFET运算放大器和与门延时实现保持时间可控的峰值保持电路。通过软件仿真对2种设计方法进行对比分析,选择更适合激光扫描仪接收系统的跨导型峰值保持电路。经实验验证,该电路可对15 ns脉宽、200 kHz重频和50 MHz带宽的信号有效保持,且保持时间可调。     

数字锁相控制的IGBT感应加热电源

以20 kHz/10 kW中频电源为设计对象,设计了采用三相不控整流和串联谐振逆变器的IGBT淬火感应电源.给出了其功率主电路器件的具体参数并通过Simulink仿真为实验装置提供了依据;根据IGBT的驱动要求,选择驱动器SKHI 22A详细研究了IGBT的驱动电路及其外围电路的设计;锁相控制电路由CD4046和DSP...     

A low-cost fiber-optic strain gage system for biologicalapplications

A new low-cost strain measurement system has been developed for the mechanical testing of biological soft tissues. The technique creates four spots of light on a tissue sample surface by piercing the tissue sample with two pairs of small light-conducting optical fibers (one pair for each axis of a biaxial stretch), terminated by high intensity infrared emitters. A large-area photodiode, located below the tissue sample, detects the light emitted from the two pairs of light-spots. Analog and digital circuitry analyze the current signal from the photodiode to determine the position of a light-spot in real time. Each infrared emitter is sequentially cycled "on" at a rate of 3 kHz and the resulting photodiode current signal, after being converted to a voltage signal, is held by an integrated circuit sample and hold amplifier. Analog differencing of pairs of light-spot voltage signals provides a final output proportional to the separation between coaxial light-spots.     

K波段推-推介质振荡器设计

为了满足现代通信系统对于高频率与高稳定性信号源的需求,提出一种K波段介质振荡器。该振荡器通过推-推结构将两路子振荡器合二为一,使其能够在一个电路中同时实现振荡器和倍频器。在介质谐振器的两条耦合微带线上增加变容二极管模块,通过改变变容二极管的偏置电压调整谐振器中传输信号的相位。变容二极管模块的加入能够有效降低有源器件不一致性对电路的影响,减少两个子振荡器在基频处对输出信号的干扰,同时让振荡器获得200 MHz左右的输出信号频率可调范围。测试结果表明:在输出频率为20.96 GHz时,输出功率约为-4.59 dBm,在10 kHz时达到-66.50 dBc/Hz的相位噪声,在100 kHz时达到-94.31 dBc/Hz的相位噪声,基波抑制度达到-25.42 dBc。     

次谐波调制下光注入DFB-LD结构的可调谐光电振荡器

为实现具有高频谱纯度、低相位噪声的宽带可调谐微波信号生成,提出并通过实验验证了一种次谐波信号调制下光注入半导体激光器结构的光电振荡器,其原理为通过利用光注入半导体激光器的单周期（P1）振荡工作状态和波长选择放大特性实现可调微波信号生成,并进一步通过在光电振荡环路中引入次谐波信号调制对系统生成微波信号的频率稳定性、边模抑制比与频谱纯度进行优化。实验结果表明,文中方案提出的光电振荡器可以生成输出功率大于5 dBm,频率调谐范围为12~18 GHz的微波信号。同时,系统生成的微波信号的3 dB带宽为100 kHz,边模抑制比可达 51 dB,且信号在频偏量为100 Hz和10 kHz处的相位噪声分别为?78 dBc/Hz和?109 dBc/Hz。此外,光电振荡器生成微波信号的频率调谐范围只受系统中使用的各类光电器件工作带宽的限制,通过采用具有更大带宽的光电器件可以实现更高频率的微波信号生成。