一款面向IP的11位160兆采样率双通道电流舵数模转换器的设计

This paper presents an 11-bit 160 MS/s 2-channel current-steering digital-to-analog converter(DAC)IP. The circuit and layout are carefully designed to optimize its performance and area. A 6-2-3 segmented structure is used for the trade-off among linearity, area and layout complexity. The sizes of current source transistors are calculated out according to the process matching parameter. The unary current cells are placed in a one-dimension distribution to simplify the layout routing, spare area and wiring layer. Their sequences are also carefully designed to reduce integral nonlinearity. The test result presents an SFDR of 72 d Bc at 4.88 MHz input signal with DNL 60.25 LSB, INL 6 0.8 LSB. The full-scale output current is 5 m A with a 2.5 V analog power supply. The core of each channel occupies 0.08 mm2 in a 1P-8M 55 nm CMOS process.     

Study of energy transfer in silicon-based micro-ring resonators

Physical model, time-domain model, transmission spectra and energy transfer diagram of silicon-based micro-ring resonators based on the parallel waveguide structure are analyzed in this paper, in which transmission spectrum is ob- tained by Matlab, and the energy transfer process is analyzed by Rsoft. According to the analyses of the models and results, the energy transfer process in this type of resonator is clear to a great extent. The experimental results show that when the input signal is stable, the energy of the micro-ring resonator and the drop port tends to be steady after the input optical signal is coupled in the coupling region, which proves that the silicon-based micro-ring resonators can select specific optical signal if the input optical signal satisfies the resonance condition. However, if the resonance condition is not met, filtering function, optical switch function and signal selection function can be realized. Therefore, the analysis and simulation of energy transfer in silicon-based micro-ring resonators can not only enrich the silicon micro-ring resonator theory, but also provide new theoretical basis and method for the design and optimization of ex- isting, ontoelectronie devices.     

ANALYSIS OF RECTANGULAR MICROSTRIP PATCH ANTENNA COVERED WITH N-DIELECTRIC LAYERS

A generalized spectral Green's function formulation of N-layer substrate structure is given with three dimension sources, which is a set of closed form formulas. A full-wave analysis model for rectangular microstrip antennas covered with N-dielectric layers has been established by using the above spectral Green's function. The unknown surface current density on the niicrostrip patch for such structure is found as a solution of an integral equation. The input VSWR and radiation patterns of the antenna are also obtained. The numerical results have been verified by the experimental results.     

一种新型的基于开关电容相关双采样的带隙基准电路

A switched capacitor bandgap voltage reference with correlated double sampling structure embedded in a temperature sensor is implemented in a standard 0.35μm CMOS process.Due to the smaller change of the op-amp’s output voltage,this topology is very suitable for low power applications.In addition,errors caused by the finite op-amp gain,input offset voltage,and 1/f noise are eliminated with the correlated double sampling technique.Additionally,two-level process calibration techniques are designed to minimize the process spread. Finally,a method of getting a full period valid reference voltage output is discussed and experimental results are provided to verify the effectiveness of the proposed structure.     

A 12 bit 100 MS/s pipelined analog to digital converter without calibration

A 1.8 V 12 bit 100 MS/s pipelined analog to digital converter(ADC) in a 0.18μm complementary metal-oxide semiconductor process is presented.The first stage adopts a 3.5 bit structure to relax the capacitor matching requirements.A bootstrapped switch and a scaling down technique are used to improve the ADC's linearity and save power dissipation,respectively.With a 15.5 MHz input signal,the ADC achieves 79.8 dB spurious-free dynamic range and 10.5 bit effective number of bits at 100 MS/s.The power consumpt...     

Photoacoustic Doppler flowmetry of carbon particles flow using an autocorrelation method

The potential capability of low coherence backscattering（LBS） is explored to determine the anisotropy factor based on azimuthal light backscattering map. The scattering intensity signal measured at azimuthal angle φ=0° is extracted for analysis. By performing nonlinear regression fitting on the experimental signal to the Henyey-Greenstein phase function, the anisotropy factor is determined. The experiments with tissue phantom consisting of the aqueous suspension of polystyrene microspheres are carried out. The results show that the measured anisotropy factor is well described by Mie theory.     

60 V tolerance full symmetrical switch for battery monitor IC

For stacked battery monitoring IC high speed and high precision voltage acquisition requirements, this paper introduces a kind of symmetrical type high voltage switch circuit. This kind of switch circuit uses the voltage following structure, which eliminates the leakage path of input signals. At the same time, this circuit adopts a high speed charge pump structure, in any case the input signal voltage is higher than the supply voltage, it can fast and accurately turn on high voltage MOS devices, and convert the battery voltage to an analog to digital converter. The proposed high voltage full symmetry switch has been implemented in a 0.18μm BCD process; simulated and measured results show that the proposed switch can always work properly regardless of the polarity of the voltage difference between the input signal ports and an input signal higher than the power supply.     

Novel closed-form resistance formulae for rectangular interconnects

Two closed-form formulae for the frequency-dependent resistance of rectangular cross-sectional interconnects are presented.The frequency-dependent resistance R(f) of a rectangular interconnect line or a interconnect line with a ground plane structure is first obtained by a numerical method.Based on the strict numerical results, a novel closed-form formula R(f) for a rectangular interconnect alone is fitted out using the Levenberg-Marquardt method.This R(f) can be widely used for analyzing on-chip power grid IR-drop when the frequency is changing. Compared to the previously published R(f) formula for an interconnect,the formula provided here is more accurate during the frequency transition range.Also for a bigger width to thickness ratio,this formula shows greater accuracy and robustness.In addition,this paper fits out the closed-form R(f) formula for a micro-strip-like interconnect (an interconnect with a ground plane),which is a typical structure in the on-chip or package power delivery system.     

A Matrix Formulation of Discrete Chirp Fourier Transform Algorithms

This work presents a computational matrix framework in terms of tensor signal algebra for the formulation of discrete chirp Fourier transform algorithms.These algorithms are used in this work to estimate the point target functions(impulse response functions)of multiple-input multiple-output(MIMO)synthetic aperture radar(SAR)systems.This estimation technique is being studied as an alternative to the estimation of point target functions using the discrete cross-ambiguity function for certain types of environmental surveillance applications.The tensor signal algebra is presented as a mathematics environment composed of signal spaces,finite dimensional linear operators,and special matrices where algebraic methods are used to generate these signal transforms as computational estimators.Also,the tensor signal algebra contributes to analysis,design,and implementation of parallel algorithms.An instantiation of the framework was performed by using the MATLAB Parallel Computing Toolbox,where all the algorithms presented in this paper were implemented.     

Removal of Ocular Artifacts from Electroencephalo-Graph by Improving Variational Mode Decomposition

Ocular artifacts in Electroencephalography(EEG)recordings lead to inaccurate results in signal analysis and process.Variational Mode Decomposition(VMD)is an adaptive and completely nonrecursive signal processing method.There are two parameters in VMD that have a great influence on the result of signal decomposition.Thus,this paper studies a signal decomposition by improving VMD based on squirrel search algorithm(SSA).It’s improved with abilities of global optimal guidance and opposition based learning.The original seasonal monitoring condition in SSA is modified.The feedback of whether the optimal solution is successfully updated is used to establish new seasonal monitoring conditions.Opposition-based learning is introduced to reposition the position of the population in this stage.It is applied to optimize the important parameters of VMD.GOSSA-VMD model is established to remove ocular artifacts from EEG recording.We have verified the effectiveness of our proposal in a public dataset compared with other methods.The proposed method improves the SNR of the dataset from-2.03 to 2.30.     

Phase derivative distribution of signal and Gaussian noise sum

Characteristic function and integral function of the phase derivative distribution of harmonic signal and narrowband Gaussian noise sum are obtained for the case when the signal’s central frequency coincides with the central frequency of noise spectrum. It is shown that the power series for the distribution density of the phase derivative is determined by odd moments of the envelope.     

自适应旋转投影分解法

本文提出种新的时－频分解方法－自适应旋转投影分解法。在表征信号空间的线性调频高斯信号集上，我们针对原始信号自适应地搜索出一组与信号匹配最好的基函数序，以此 用尽可能少的基函数来重构信号子空间。     

What are the analytical conditions for which a blind equalizer will loose the convergence state?

In this paper, I propose for the noiseless, real and two independent quadrature carrier case some approximated conditions on the step-size parameter, on the equalizer’s tap length and on the channel power, related to the nature of the chosen equalizer and input signal statistics, for which a blind equalizer will not converge anymore. These conditions are valid for type of blind equalizers where the error that is fed into the adaptive mechanism that updates the equalizer’s taps can be expressed as a polynomial function of the equalized output of order three like in Godard’s algorithm. Since the channel power is measurable or can be calculated if the channel coefficients are given, there is no need anymore to carry out any simulation with various step-size parameters and equalizer’s tap length for a given equalization method and input signal statistics in order to find the maximum step-size parameter for which the equalizer still converges.     

Beamforming algorithm for circular antenna array immune to multipath propagation and non-stationary interference sources

A circular antenna array beamforming algorithm with extended zeros based on using correlation function of antenna array, which should provide continuous uniform or Gaussian angular signal’s energy distribution along the given direction, is presented.     

Analysis of rectangular microstrip patch antenna covered with N-dielectric layers

A generalized spectral Green’s function formulation of N-layer substrate structure is given with three dimension sources, which is a set of closed form formulas. A full-wave analysis model for rectangular microstrip antennas covered with N-dielectric layers has been established by using the above spectral Green’s function. The unknown surface current density on the microstrip patch for such structure is found as a solution of an integral equation. The input VSWR and radiation patterns of the antenna are also obtained. The numerical results have been verified by the experimental results. Partly supported by the Research Item B96(56) of the Ministry of Railways of China     

A detection method of laser doppler signal based on topological contravariance

To detect the laser doppler signal, the unknown signal is tracked by the known signal using the concept of topological contravariance. The unknown topological space U and known space M are founded, and then the unknown signal＇s transformation is tracked dynamically according to this mapping relationship between the two spaces. The system equation is obtained by gradient-descent method, and the conditions of stability are given by Poincare mapping. The proposed method is applied to measure the in-plane displacement signal of the solid 50 m away using laser doppler, signal The result proves that the method can detect laser doppler, signal accurately, its relative error is less than 0.7%.     

The near-field thermal microwave radiation response of a biological object to the local change of the lateral temperature distribution

A layer-by-layer method is theoretically developed for reconstructing the temperature distribution inside a biological object from the measured outgoing thermal microwave radiation energy flux. The measurement is carried out along the plane parallel to the heated object surface in the surface’s near-field area. The equation of the inverse problem is obtained. The equation couples the 2D spatial Fourier-component of Poynting’s outgoing radiation vector with the similar Fourier-component of the lateral temperature distribution along elementary inner layers parallel to the object surface. The obtained equation is solved for the case of a 1D periodic or local depth-uniform lateral temperature distribution inside an object. The effective half-width of the spatial-harmonic spectrum for the outgoing thermal radiation energy flux is shown to be estimated by the double wave number inside the object. At the same time, the spatial half-width of a biological object’s thermal-radiation response to a local change in the lateral temperature distribution is estimated as a half of the wavelength inside the object. This result justifies the antenna size conventionally applied in biomedical research.     

Multi-band microwave photonic satellite repeater scheme employing intensity Mach-Zehnder modulators

To solve the satellite repeater's flexible and wideband frequency conversion problem, we propose a novel microwave photonic repeater system, which can convert the upload signal's carrier to six different frequencies. The scheme employs one 20 GHz bandwidth dual-drive Mach-Zehnder modulator (MZM) and two 10 GHz bandwidth MZMs. The basic principle of this scheme is filtering out two optical sidebands after the optical carrier suppression (OCS) modulation and combining two sidebands modulated by the input radio frequency (RF) signal. This structure can realize simultaneous multi-band frequency conversion with only one frequency-fixed microwave source and prevent generating harmful interference sidebands by using two corresponding optical filters after optical modulation. In the simulation, one C-band signal of 6 GHz carrier can be successfully converted to 12 GHz (Ku-band), 28 GHz, 34 GHz, 40 GHz, 46 GHz (Ka-band) and 52 GHz (V-band), which can be an attractive method to realize multi-band microwave photonic satellite repeater. Alternatively, the scheme can be configured to generate multi-band local oscillators (LOs) for widely satellite onboard clock distribution when the input RF signal is replaced by the internal clock source.     

Computation of Dyadic Green’s functions for generalized cylinders in free space

Dyadic Green’s functions are powerful and efficient for solving the boundary problems in electromagnetic theory. The key problem involved is how to deal with the additional term in the electric dyadic Green’s function at the source region. In this paper, the dyadic Green’s functions for generalized cylinders in free space are derived with the technique in another paper of author (1984). The dyadic Green’s functions for conducting wedges, half-plates and elliptic cylinders, whose integral of continuous spectrumh has been eliminated, are given particularly.     

Closed-Form Expressions of Multilayered Planar Green's Functions That Account for the Continuous Spectrum in the Far Field

The rational function fitting method has been found useful in the derivation of closed-form expressions of spatial-domain Green's functions for multilayered media. However, former implementations of the rational function fitting method lead to Green's functions expressions that are not accurate in the far field when this far field is dominated by the continuous spectrum instead of being dominated by surface waves (as it happens, for instance, in the case of lossy multilayered media). In this paper, the authors introduce a novel implementation of the rational function fitting method, which leads to Green's functions expressions that are accurate in the far field when this is dominated either by the continuous spectrum or by surface waves. In the new approach, the far-field contribution of the continuous spectrum to the Green's functions is numerically fitted in terms of functions with closed-form Hankel transforms, and this far-field contribution is explicitly added to the total least squares approximations of the Green's functions. The numerical results obtained for the Green's functions with the new approach have been compared with numerical results obtained via direct numerical integration of Sommerfeld integrals, and excellent agreement has been found despite the contribution—continuous spectrum or surface waves—dominating the far field.