Integrated balanced sampling circuit for ultra-wideband communications and radar systems

A balanced sampling circuit realized using step recovery and Schottky diodes on coplanar waveguide, coplanar strips, and slotlines is presented for ultra-wideband communications and radar applications. An efficient design was implemented to achieve improved performance. The impulse generator, providing signal for the sampling gate, was designed with a new LO feeding structure. The fabricated circuit shows 16-19 dB conversion loss without amplifier and 1-4 dB conversion gain with amplifier across 9-GHz RF bandwidth with 500-MHz sampling frequency.     

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.     

HgCdTe sampling circuit

The demonstration, using HgCdTe MISFETs, of a sampling circuit with output buffer amplifier is reported. Using the circuit, correlated double sampling is demonstrated at speeds typical of those required for focal plane arrays. Using a swept sine input, the circuit's transfer function is verified. The circuit was fabricated on epitaxially grown HgCdTe, with a cutoff wavelength of 3.56 mu m at 77 K.<>     

容差分析在舵机反馈采样控制电路中的应用

基于空空导弹对精确控制的要求,以及电路容差分析2种方法的基本原理,结合某空空导弹舵机反馈采样控制电路,提出了基于Saber软件进行电路容差分析方案。采用Saber软件研究电路参数偏差的容差仿真分析方法 ,具体分析了电位器±10%的精度是制约舵反馈电路容差能力的重要因素,并提出提高电路可靠性设计措施。     

基于DSP的无功补偿控制系统采样电路的设计

针对目前配网中电压与电流较难实时测量的问题,详细介绍了MCR的无功补偿控制系统采样电路的设计思想,设计出基于DSP采样的硬件电路,对硬件电路设计上进行了优化,对硬件的可靠性详细的分析。由于滤波以及触发信号的时间基准问题,同时也设计了相位补偿硬件电路以及过零检测硬件电路。实验结果表明采样电路、相位补偿电路和过零检测电路解决了MCR的无功补偿控制系统中电压、电流采样问题以及晶闸管触发信号的时间基准问题。     

Two-dimensional random adaptive sampling for image scanning

An efficient sampling algorithm for image scanning is proposed, suitable to represent "interesting" objects, defined as a set of spatially close measured values that springs out from a background noise (as in applied geophysics in the process of anomaly detection). This method generates a map of pixels randomly distributed in the plane and able to cover all the image with a reduced number of points with respect to a regular scanning. Simulation results show that a saving factor of about 50% is obtained without information loss. This result can be proved also by using a simplified model of the sampling mechanism. The algorithm is able to detect the presence of an object emerging from a low energy background and to adapt the sampling interval to the shape of the detected object. In this way, all of the interesting objects are well represented and can be adequately reconstructed, while the roughly sampling in the background produces an imperfect reconstruction. Simulation results show that the method is feasible with good performances and moderate complexity.     

An intelligent power amplifier MMIC using a new adaptive bias control circuit for W-CDMA applications

A high-linearity and high-efficiency MMIC power amplifier is proposed that adopts a new on-chip adaptive bias control circuit, which simultaneously improves efficiency at the low output power level and linearity at the high output power level. The adaptive bias control circuit detects the input power level and supplies a low quiescent current of 16 mA at the low output power level and an increased current up to 90 mA according to the increased power level adaptively. The intelligent W-CDMA power amplifier using the adaptive bias circuit exhibits an improvement of average power usage efficiency of more than 1.93 times, and an adjacent channel leakage ratio by 4 dB at the output power of 28.3 dBm.     

Integrated reconfigurable high-voltage transmitting circuit for CMUTs

In this paper a high-voltage transmitting circuit aimed for capacitive micromachined ultrasonic transducers (CMUTs) used in scanners for medical applications is designed and implemented in a 0.35 \(\upmu\)m high-voltage CMOS process. The transmitting circuit is reconfigurable externally making it able to drive a wide variety of CMUTs. The transmitting circuit can generate several pulse shapes with voltages up to 100 V, maximum pulse range of 50 V, frequencies up to 5 MHz and different driving slew rates. Measurements are performed on the circuit in order to assess its functionality and power consumption performance. The design occupies an on-chip area of 0.938 mm\(^{2}\) and the power consumption of a 128-element transmitting circuit array that would be used in an portable ultrasound scanner is found to be a maximum of 181 mW.     

Integrated circuit array antenna for short-range communicationsystems

A novel active array antenna for short-range communication applications is presented. Each element of the array consists of a `cold' MESFET which performs both the ASK demodulator and the DPSK reflection modulator functions and which is directly mounted on a rectangular microstrip resonator. The techniques used to fabricate this active antenna provide good performance at low cost and low power consumption     

Current-mode linguistic hedge circuit for adaptive fuzzy logiccontrollers

A CMOS current-mode linguistic hedge `very' circuit which can be applied to adjust the membership function of a fuzzy set for obtaining adaptive fuzzy logic control is proposed. The design constraints of the proposed circuit are also discussed. Simulation results show that this circuit has high speed, large dynamic range and high accuracy     

Integrated circuit yield statistics

The random failure statistics for the yield of mass-produced semiconductor integrated circuits are derived by considering defect and fault formation during the manufacturing process. This approach allows the development of a yield theory that includes many models that have been used previously and also results in a practical control model for integrated circuit manufacturing. Some simpler formulations of yield theory that have been described in the literature are compared to the model. Application of the model to yield management are discussed and examples given.     

Designing better adaptive sampling algorithms for ECG Holtersystems

Let Ψ be any adaptive sampling algorithm that can run in real time on a tapeless multichannel electrocardiogram (ECG) Holter system. Simple methods which can significantly improve Ψ's fidelity are described and their results are compared in this paper. It is shown that by adding some simple tests to Ψ, the signals reconstructed by Ψ can be improved as much as 5.45 dB. It is also shown that under the same data rate, a good data compressor with slowly sampled input ECG is preferable to a bad data compressor with highly sampled input ECG     

一种无刷直流电机电流采样及保护电路的设计

针对某型号无刷直流电机的控制要求,本文设计了一种高精度采样及保护电路,该电路可以对无刷直流电机工作时的三相电流进行实时采集,以便于控制系统进行闭环控制,并对电机和控制系统快速实施保护.最后通过实验证明了该电路精度高、可靠性好,可以有效的保障控制系统和电机的正常运行.     

New adaptive law for robust adaptive control

The authors present a new adaptive law for robust adaptive control, using the e²-modification term in place of the e-modification term in the adaptive law, to improve the robustness of the adaptive system. Simulation results show that the adaptive law with the e²-modification yields improved performance as compared with the e-modification     

Blind adaptive sampling of images

Adaptive sampling schemes choose different sampling masks for different images. Blind adaptive sampling schemes use the measurements that they obtain (without any additional or direct knowledge about the image) to wisely choose the next sample mask. In this paper, we present and discuss two blind adaptive sampling schemes. The first is a general scheme not restricted to a specific class of sampling functions. It is based on an underlying statistical model for the image, which is updated according to the available measurements. A second less general but more practical method uses the wavelet decomposition of an image. It estimates the magnitude of the unsampled wavelet coefficients and samples those with larger estimated magnitude first. Experimental results show the benefits of the proposed blind sampling schemes.     

Implementation of LLCC-resonant driving circuit and adaptive CMAC neural network control for linear piezoelectric ceramic motor

In this paper, an adaptive cerebellar-model articulation computer (CMAC) neural network (NN) control system is developed for a linear piezoelectric ceramic motor (LPCM) that is driven by an LLCC-resonant inverter. The motor structure and LLCC-resonant driving circuit of an LPCM are introduced initially. The LLCC-resonant driving circuit is designed to operate at an optimal switching frequency such that the output voltage will not be influenced by the variation of quality factor. Since the dynamic characteristics and motor parameters of the LPCM are highly nonlinear and time varying, an adaptive CMAC NN control system is designed without mathematical dynamic model to control the position of the moving table of the LPCM drive system to achieve high-precision position control with robustness. In the proposed control scheme, the dynamic backpropagation algorithm is adopted to train the CMAC NN online. Moreover, to guarantee the convergence of output tracking error for periodic commands tracking, analytical methods based on a discrete-type Lyapunov function are utilized to determine the optimal learning-rate parameters of the CMAC NN. The effectiveness of the proposed driving circuit and control system is verified by experimental results in the presence of uncertainties, and the advantages of the proposed control system are indicated in comparison with a traditional integral-proportional position control system. Accurate tracking response and superior dynamic performance can be obtained due to the powerful online learning capability of the CMAC NN with optimal learning-rate parameters.     

抗干扰电流采样电路的设计

电流采样不仅应用于电压模DC-DC转换器的过流保护电路中,更广泛地应用于电流模DC-DC转换器的电流控制环路中。本文针对集成电流模DC-DC转换器的高速电流采样抗干扰性差的问题,提出了一种解决方案,利用辅助采样、干扰对消的方法,来消除电源扰动和开关管寄生效应对采样电流的影响,并利用Cadence软件对所设计电路进行了仿真。仿真结果表明,基于对消法的抗干扰电流采样电路能够很好地消除开关管寄生效应的影响,能够大部分消除电源电压扰动对采样电流的影响。