CPLD和多周期同步测频法在多普勒频率测量系统中的应用

在某相位编码毫米波雷达系统中,要求很高的目标速度测量精度,因而目标多普勒频率测量电路的设计比较重要.多周期同步测量方法作为在直接测频基础上发展起来的新方法,在测频系统中得到越来越广泛的应用.文中介绍了利用复杂可编程逻辑器件(CPLD)以及多周期同步测频方法实现目标多普勒频率的测量.实际使用表明,该设计具有系统集成度高、精度高、可靠等优点.     

An improved two-frequency method of capacitance measurement forSrTiO3 as high-k gate dielectric

An improved two-frequency method of capacitance measurement for the high-k gate dielectrics is proposed. The equivalent circuit model of the MOS capacitor including the four parameters of intrinsic capacitance, loss tangent, parasitic series inductance, and series resistance is developed. These parameters can be extracted by independently measuring the capacitor at two different frequencies. This technique is demonstrated for high-k SrTiO₃ gate dielectrics and the results show that the calibrated capacitances are invariant over a wide range of frequency. In addition, the extracted loss tangent, inductance and resistance are independent on gate voltage and frequency. The effect of series resistance on the frequency dispersion of the capacitance can be also explained by this model. These results indicate that this modified technique can be incorporated in the routine capacitance-voltage (C-V) measurement procedure providing the physically meaningful data for the high-k gate dielectrics     

RLC串联谐振电路的实验研究

从RLC串联谐振电路的方程分析出发,推导了电路在谐振状态下的谐振频率、通频带、品质因数和输入阻抗,并且基于Multisim 10仿真软件创建RLC串联谐振电路,利用其虚拟仪表和仿真分析,分别用测量及仿真分析的方法验证它的理论根据。其结果表明了仿真与理论分析的一致性,为仿真分析在电子电路设计中的运用提供了一种可行的研究方法。     

A novel technique to determine the gate and drain bias dependentseries resistance in drain engineered MOSFETs using one single device

A new measurement method is explained for the extraction of the source and drain series resistance of drain engineered MOSFETs from their low frequency ac characteristics as a function of gate and drain bias using only one single MOSFET. Experimental results indicate, the effect of drain voltage dependent series resistance is relevant both in the ohmic and in the saturation region of the MOSFET. In addition the new measurement method is extended in such a way that it can be used to measure the series resistance as a function of gate bias only at low drain bias. Comparison of this single transistor measurement technique with other methods, needing a set of identical transistors with different channel lengths, shows that our method gives equal results. Finally attention is also given to the modeling of the series resistance in the ohmic and saturation region. For both regions simple, accurate compact model expressions have been derived     

匀加速直线运动目标脱靶量测量方法

本文研究了匀加速直线运动目标的脱靶量测量问题.文中通过建立脱靶量测量方程,将匀加速直线运动目标的脱靶量测量表示为交会过程多普勒频率时间序列的非线性最小二乘拟合问题,并讨论了其求解的非线性优化算法.仿真表明,该多普勒脱靶量测量方法可消除基于匀速直线运动模型所存在的脱靶量测量的系统误差.     

Determining transfer functions, especially at high frequencies

Previous results for time delay and rise are generalised to a method for determining all the coefficients of the transfer function in a Taylor series expansion about zero frequency. The method involves integrations of the type with which picosecond accuracies were previously obtained in time delay measurement. Comparable time scale accuracies can be expected for the method described.     

特高频率测量新技术的研究

特高频率的测量是频率测量中的难点之一.所有针对特高频率测量最基本的方法都是建立在对频率信号处理的基础上,而最常用的处理方法是混频或谐波混频的方法.在利用该方法测量特高频率时是非常困难的,因为对高频进行倍频或分频是十分困难的,从而也就造成了特高频测量的主要困难.有人利用示波器实现了大频率比(105)的比对测量.该文对这种比对测量的方案做了进一步的分析,通过研究分析以及实验验证,指出了一种特高频测量的新思路.即采用变换测量的方式,将对很难测量的特高频的测量转变成对一种与之有一定对应关系且便于测量的对应量的测量.设计了一种对THz进行测量的原理框图,并对其做了分析说明.     

基于CPLD和89S51的多功能信号测量仪

提出一种基于CPLD和89S51的多功能信号测量仪,该测量仪可测量频率,周期和脉宽等参数.介绍了高精度测频方法、可编程逻辑器件应用以及周期脉宽测量方法.以CPLD和单片机为核心,消除了直接测频方法对测量频率需采用分段测试的局限性,该多功能信号测量仪可在整个测试频段内保持高精度,测量频率范围达0.1Hz~100MHz以上.     

Improving time-domain measurements with a network analyzer using arobust rational interpolation technique

A method to efficiently and accurately compute a time-domain waveform from a network-analyzer frequency-domain measurement is presented in this paper. The method is based on a robust interpolation technique to construct a pole-residue representation of the response of the device-under-test. First, the rational function is expressed in terms of Chebyshev polynomials, instead of the usual power series, to accurately determine the poles of the network over a wide frequency range. The properties of a passive system are then utilized to efficiently calculate the residues. The resulting pole-residue model is analytically transformed to obtain the time-domain response in any time window, beyond the limitations of the discrete Fourier transform (DFT) technique. Unlike the DFT technique, the method does not require a large number of equally spaced harmonically related frequency points. The parametric model can also be used to economically store large measurement data. The proposed procedure is computationally inexpensive and less sensitive to numerical instability. To illustrate the validity of the method, examples of frequency- and time-domain measurements of a Beatty structure and simulation data of a low-pass Butterworth filter are given     

基于光学频率梳光谱干涉实现水的群折射率测量

基于光学频率梳的光谱干涉,本文提出了一种水的群折射率的测量方法,可以高精度地测量水的群折射率;分析了水的群折射率的测量原理;搭建了基于518 nm光学频率梳的实验装置,进行了群折射率的测量实验;实验结果表明,本文提出的测量方法可以实现水的群折射率的高精度测量;与参考值比对的结果表明,测量不确定度在10-5量级。     

Characterization of on-chip balun with patterned floating shield in 65 nm CMOS

A simple method of balun synthesis is proposed to estimate the balun structure in the operating frequency band.Then,a careful optimization is implemented to evaluate the estimated structure by a series of EM simulations. In order to investigate the impact of the patterned floating shield(PFS),the optimized baluns with and without PFS are fabricated in a 65 nm 1P6M CMOS process.The measurement results demonstrate that the PFS obviously improves the insertion loss(IL) in the frequency range and a linear improving trend appears smoothly.It is also found that the PFS gradually improves the phase balance as the frequency increases,while it has a very slight influence on the magnitude balance.To characterize the device’s intrinsic power transfer ability,we propose a method to obtain the baluns’ maximum available gain directly from the measured 3-port S-parameters and find that IL-comparison may not be very objective when evaluating the shielding effect.We also use the resistive coupling efficiency to characterize the shielding effect,and an imbalanced shielding efficiency is found though the PFS is perfectly symmetric in the measurement.It can be demonstrated that this phenomenon comes from the intrinsic imbalance of our balun layout.     

超高速VLSI中多晶硅发射极晶体管串联电阻的测量

本文对目前流行的测量晶体管串联电阻的常规方法进行了理论分析和实验验证，结果表明，用常规方法测量多晶硅发射极晶体管串联电阻的误差很大。     

双通道外场RCS测量雷达研究

针对外场雷达目标散射特性测试的需要,设计并实现了一种外场测量雷达。该雷达可在外场以频分的方式在2个固定频段上同时进行雷达散射截面的测量,以及在转台的配合下进行二维成像测试。采用脉间变频技术,避免了线形扫频方法非线性引起的问题,通过现场可编程器件的使用,可灵活设置调制脉冲和硬件距离门,最大限度地消除外场虚假信号和背景杂波的影响,可采用校准支路实时对正交解调的误差进行校准。     

高次泛音比法测定厚度振动机电耦合系数

压电振子低频振动模式的高次泛音易与厚度振动模式的基频相耦合,导致厚度振动的基音串联谐振频率不能精确测量(或无法测量),造成传统泛音比法测定压电振子的机电耦合系数的精度和一致性变差或无法进行测定。为了克服传统泛音比法的这一弊端,提出了测定压电振子厚度振动机电耦合系数的高次泛音比法。此法通过测定3次和3次以上的高次串联谐振频率,用高次泛音比来测定压电振子厚度振动机电耦合系数。实验表明,与传统泛音比法相比,高次泛音比法具有精确度高和一致性好的明显优势。为了便于高次泛音比法的应用,提供了高次泛音比和机电耦合系数的对应表。     

拟合驻波图形实现毫米波自动测频的研究

根据在短路波导中驻波与频率相关的基本事实,本文利用运动探针在开槽波导上一系列固定位置处的检波电压来拟合驻波图形,实现毫米波的自动测频。文中给出了实施方案,讨论了主要误差修正和取样点的布置原则,并完成了方案模拟实验。     

Broad-Band Calorimeters for the Measurement of Low and Medium Level Microwave Power II.Construction and Performance

The construction and performance of a series of rugged, broad-band twin-Joule calorimeters, using dry loads, are described.These calorimeters operate over the frequency range of 0 to 75,000mc. The over-all measurement error, computed as the rms value of the maximum individual errors from known independent sources, is shown to lie between 1 and 21/2 per cent for power levels between 1 and 100mw. Power measuring techniques are discussed and a method using the heating and cooling cycle of the calorimeter is described in detail. Power comparison measurements between the calorimeters and several bolometer mounts illustrate the increasing inefficiency of bolometer mounts with increasing frequency.     

基于MC8051 IP核的多周期同步测频改进

分析多周期同步测频原理及误差,在此基础上提出一种多周期同步测频的改进方法。该方法通过对标准频率计数值的修正,在不提高系统时钟频率和闸门时间的前提下,实现了测量精度的提高,并详细分析了其测量误差。最后,讨论了在FPGA中利用MC8051 IP核来实现真正意义的高性价比的SoPC频率测量问题。     

Computer-Aided Large-Signal Measurement of IMPATT-Diode Electronic Admittance

A technique for the measurement of the Iarge-signal electronic admittance of IMPATT diodes as a function of frequency and RF voltage level using the network analyzer is described. The method de-embeds the admittance of the active region of the device from the mounting and measurement circuitry without physical disturbance of the diode. The small series resistance of the diode at breakdown is included in the embedding network together with the mount and diode package parameters. The determination of transformation networks between the measurement port and the active chip through a simple calibration procedure, a knowledge of the diode admittance below breakdown, and computer-aided optimization constitute the de-embedding procedure. Experimental electronic admittance curves are given for a low-power (100-mW) silicon IMPATT diode in the frequency range 5.7-6.5 GHz and with RF voltage levels applied across the active chip in the range 0-24 V, with an estimated error of less than 20 percent (typically 5 percent) in admittance values.     

I(t) technique for generation rate determination in implanted MOSstructures

A technique for evaluating the generation rare profile of MOS structures based on the measurement of gate current transients at two different gate voltage waveforms in non-equilibrium nonsteady-state is presented. The method allows the evaluation of the generation rate profile in the bulk of inhomogeneously doped MOS structures without requiring knowledge of the doping profile and provides, in contrast to high frequency methods, reliable results in such cases where MOS structures with high series resistances are to be investigated     

一种双正弦信号的快速频率测量方法

信号频率测量在雷达信号处理中起到重要的作用。基于DFT和自相关理论,该文提出了一种双正弦信号频率的快速估计方法。该方法先用DFT估计其中一个频率及其幅度,以此频率对信号解调并对消该频率成分,最后利用自相关理论估计信号的频差。计算机模拟证实了方法具有精度高、测频速率快的特点。