Small Signal Circuit Model of Double Photodiodes

The transmission delay of photogenerated carriers in a CMOS- process- compatible double photodiode (DPD) is analyzed by using device simulation. The DPD small signal equivalent circuit model which includes transmission delay of photogenerated carriers is given. From analysis on the frequency domain of the circuit model the device has two poles. One has the relationship with junction capacitance and the DPD‘s load, the other with the depth and the doping concentration of the N-well in the DPD. Different depth of the Nwell and different area of the DPDs with bandwidth were compared. The analysis results are important to design the high speed DPDs.     

基于Y和Z参数表征的微波SiGe HBT小信号模型参数提取

High frequency intrinsic small-signal model parameter extraction for microwave SiGe heterojunction bipolar transistors is studied, with a focus on the main feedback elements including the emitter series resistor, internal and external base-collector capacitors as well as the base series resistor, all of which are important in determining the behavior of the device equivalent circuit. In accordance with the respective features of definition of the Y- and Z-parameters, a novel combined use of them succeeds in reasonably simplifying the device equivalent circuit and thus decoupling the extraction of base-collector capacitances from other model parameters. As a result, a very simple direct extraction method is proposed. The proposed method is applied for determining the SiGe HBT small-signal model parameters by taking numerically simulated Y- and Z-parameters as nominal ＂measurement data＂ with the help of a Taurus-device simulator. The validity of the method is preliminarily confirmed by the observation of certain linear relations of device frequency behavior as predicted by the corresponding theoretical analysis. Furthermore, the extraction results can be used to reasonably account for the dependence of the extracted model parameters on device geometry and process parameters, reflecting the explicit physical meanings of parameters, and especially revealing the distributed nature of the base series resistor and its complex interactions with base-collector capacitors. Finally, the accuracy of our model parameter extraction method is further validated by comparing the modeled and simulated S-parameters as a function of frequency.     

Research of BJMOSFET frequency characteristics

The parasitic capacitance effect and its influence to the performance have been investigated in Bipolar Junction Metal-Oxide-Semiconductor Field-Effect Transistor （BJMOSFET）. The frequency characteristic equivalent circuit and high frequency response model of BJMOSFET have been presented. The frequency characteristic of BJMOSFET is simulated using the multi-transient analytical method and PSPICE9 simulator. The conclusions that BJMOSFET owns less total capacitance, wider frequency band, better transient characteristic and better frequency responses are reached by comparing with the traditional MOSFET at the same structure parameters and bias conditions. BJMOSFET, as a novel promising high frequency device, would be desired to find application in future integrated circuit.     

An InGaAs/InP 40 GHz CML static frequency divider

Static frequency dividers are widely used as a circuit performance benchmark or figure-of-merit indicator to gauge a particular device technology’s ability to implement high speed digital and integrated high performance mixed-signal circuits.We report a 2:1 static frequency divider in InGaAs/InP heterojunction bipolar transistor technology.This is the first InP based digital integrated circuit ever reported on the mainland of China. The divider is implemented in differential current mode logic(CML) with 30 transistors.The circuit operated at a peak clock frequency of 40 GHz and dissipated 650 mW from a single -5 V supply.     

Intrinsic stability of an HBT based on a small signal equivalent circuit model

Intrinsic stability of the heterojunction bipolar transistor(HBT) was analyzed and discussed based on a small signal equivalent circuit model.The stability factor of the HBT device was derived based on a compact T-type small signal equivalent circuit model of the HBT.The effect of the mainly small signal model parameters of the HBT on the stability of the HBT was thoroughly examined.The discipline of parameter optimum to improve the intrinsic stability of the HBT was achieved.The theoretic analysis resul...     

Modeling and characterization of shielded low loss CPWs on 65 nm node silicon

Coplanar waveguides(CPWs)are promising candidates for high quality passive devices in millimeterwave frequency bands.In this paper,CPW transmission lines with and without ground shields have been designed and fabricated on 65 nm CMOS technology.A physical-based model is proposed to describe the frequency-dependent per-unit-length L,C,R and G parameters.Starting with a basic CPW structure,the slow-wave effect and ground-shield influence have been analyzed and incorporated into the general model.The accuracy of the model is confirmed by experimental results.     

40GHz InGaAs/InP CML 结构静态分频器

Static frequency dividers are widely used as a circuit performance benchmark or figure-of-merit indicator to gauge a particular device technology's ability to implement high speed digital and integrated high performance mixed-signal circuits.We report a 2:1 static frequency divider in InGaAs/InP heterojunction bipolar transistor technology.This is the first InP based digital integrated circuit ever reported on the mainland of China. The divider is implemented in differential current mode logic(CML) with ...     

Simulation and Modeling of Common Mode EMI Noise in Planar Transformers

The transformer is the key circuit component of the common-mode noise current when an isolated converter is working. The high-frequency characteristics of the transformer have an important influence on the common-mode noise of the converter. Traditionally, the measurement method is used for transformer modeling, and a single lumped device is used to establish the transformer model, which cannot be predicted in the transformer design stage. Based on the transformer common-mode noise transmission ...     

Design and simulation of optoelectronic oscillator with micro ring resonator and radio frequency amplifier modelling at 110 GHz

There is an increasing need for high performance oscillators as the faster transmission networks demand for high frequency signals. Opto-electronic oscillators (OEO) enable us to make better oscillators in terms of size, weight and power. In this paper, photonic integration is proposed for realizing the OEO with micro ring resonator (MRR) and radio-frequency (RF) amplifiers of monolithic microwave integrated circuit (MMIC), which can be used for generating 110 GHz sine wave. The OEO architecture is proposed and block diagram developed considering Silicon based MRR and three-stage RF amplifier based on GaN high-electron-mobility transistor (HEMT). A simulation model is developed according to the Klein model of MRR and is validated against the calculated performance parameters. MRR dimensions are calculated as with silicon on insulator (SOI) technology and a radius 5.27 μm for the device is derived. Free spectral range (FSR) of 48.52 nm and filter rejection ratio of 16.79 dB are obtained for this device. The proposed RF amplifier is modelled with GaN parameters derived from high frequency pinch-off model and with power amplifier considerations. The gain for this amplifier is obtained as 10.6 dB. The OEO design is developed in this project in such a way that the system can be manufactured with the existing methods.     

A novel model for a planar wideband Marchand balun

A new lumped element model for conventional Marchand baluns is presented.Analyzed by the evenand odd-mode method,the equivalent equations are derived forλ/4 coupled lines.Based on the proposed 5th-order lumped equivalent circuit forλ/4 coupled lines,the self-inductance,mutual inductive coupling and the capacitance can be calculated according to the even- and odd-mode characteristic impedance,therefore,the model parameters of the balun can be easily gained from the derived equations.To verify the model,a GaAs monolithic wideband Marchand balun was implemented and tested.The EM simulation and experimental results show a good agreement with the model simulation.This model is available in a wide frequency range and makes the design procedure of the Marchand balun faster and easier.     

太赫兹平面肖特基二极管参数模型

根据太赫兹平面肖特基二极管物理结构,在理想二极管SPICE参数模型的基础上建立了二极管小信号等效电路模型。依据该二极管等效电路模型设计了基于共面波导（CPW）去嵌方法的二极管S参数在片测试结构,并对其在0.1~50 GHz、75~110 GHz频率范围内进行了高频小信号测试,利用测试结果提取了高频下二极管电路模型中各部分电容、电阻以及电感参数。将相应的高频下电容与电阻参数分别与低频经验公式电容值和直流I-V测试提取的电阻值进行了对比,并利用仿真手段对高频参数模型进行了验证。完整的参数模型以及测试手段相较于理想二极管SPICE模型和传统的参数提取方法可以更为准确地表征器件在高频下的工作状态。该建模思路可用于太赫兹频段非线性电路的优化设计。     

Realistic equivalent circuit model of coplanar waveguide opencircuit: lossy shunt resonator network

Realistic equivalent circuit model of coplanar waveguide (CPW) open circuit is proposed and formulated as a lossy shunt resonator network based on the fact that the electromagnetic (EM) wave propagates at the transverse direction around the open-end. A "short-open calibration" (SOC) technique is applied in the full-wave method of moments (MoM) to effectively extract all the model parameters over a wide frequency range. After the extracted capacitance at low frequency is confirmed by the previous static results, extensive investigation is implemented to reveal the high-frequency dynamic features of CPW open circuit, e.g., shunt resonance and radiation loss. A CPW open-end circuit is then fabricated and measured to provide an experimental verification of the proposed model     

One- and two-dimensional coplanar waveguide structures with multiple-frequency-tuned slot resonators

In this letter, a new multiple-frequency-tuned slot resonator is introduced in coplanar waveguide (CPW) technology. Its equivalent circuit model is built up and its frequency characteristics are explained by employing the equivalent circuit parameters and field analysis. Furthermore, one-dimensional (1-D) and 2-D CPW structures with the proposed slot resonator are designed. Measurements show that the proposed CPW structures with compact size exhibit good multiple-stopband behaviours.     

Broadband electronically tunable planar active radiating elementsand spatial power combiners using notch antennas

A Gunn device has been integrated with two types of active planar notch antennas. The first types uses a coplanar waveguide (CPW) resonator an a stepped-notched antenna with bias tuning to achieve a bandwidth of 275 MHz centered at 9.33 GHz with a power output of 14.2±1.5 dBm. The second type uses a CPW resonator with a varactor for frequency tuning to achieve a bandwidth of over 1.3 GHz centered at 9.6 GHz with a power output of 14.5±0.8 dBm. This is equivalent to over 14% electronic tuning bandwidth. Both configurations exhibit a very clean and stable output signal. A theoretical circuit model was developed to facilitate the design. The model agrees well with experimental results. Injection-locking experiments on the second configuration show a locking gain of 30 dB with a locking bandwidth of 30 MHz at 10.2 GHz. Power combining experiments of two-varactor-tuned CPW active notch antenna elements in a broadside configuration have achieved well over 70% combining efficiency throughout the wide tuning range. The circuits have advantages of small size, low cost, and excellent performance     

Resonant-type balanced composite right/ left-handed coplanar waveguide structure

A resonant-type balanced composite right/left-handed (CRLH) coplanar waveguide (CPW) structure based on split ring resonators (SRRs) is presented. An equivalent circuit model is used to describe its complicated behaviour. As the higher cutoff frequency of the left- handed (LH) band and the lower cutoff frequency of the right- handed (RH) band are identical, a continuous transition from LH band to RH band without a bandgap can be achieved. In addition, because of the presence of SRRs, the resonant-type balanced CRLH CPW structure exhibits a very sharp cutoff in the lower edge of the transmission band.     

Characterisation and modelling of mitered coplanar waveguide bends on silicon substrate

Mitered coplanar waveguide (CPW) bends are cascaded to form meandered CPW lines. Test samples are fabricated and characterised. In this article a compact, CAD-oriented semi-empirical equivalent circuit model is presented. The validity of the model is verified by comparing it with the experimental and simulation results. It is demonstrated that a meandered CPW with mitered bends has higher characteristic impedance and lesser loss when compared to straight CPWs.     

共面波导不连续结构EC-ANN模型的电路设计与实现

将一种精确高效的等效电路训练人工神经网络模型引入共面波导不连续性结构建模.该建模算法继承了等效电路模型和电磁仿真人工神经网络模型的优点.此次开发并得到验证的共面波导不连续性结构模型包括:台阶段、叉指电容、对称十字节和螺旋电感.这些模型嵌入CAD仿真工具可以完成电路的设计、仿真和优化,最后通过一个GaAs工艺的共面波导带通滤波器的设计与实现验证了模型的有效性.     

Theoretical and experimental characterization of coplanar waveguidediscontinuities for filter applications

A full-wave analysis of shielded coplanar waveguide (CPW) two-port discontinuities based on the solution of an appropriate surface integral equation in the space domain is presented. Frequency-dependent scattering parameters for open-end and short-end CPW stubs are computed using this method. The numerically derived results are compared with measurements performed in the frequency range 5-25 GHz and show very good agreement. From the scattering parameters, lumped-element equivalent circuits have been derived to model the discontinuities. The inductors and capacitors of these models have been represented by closed-form equations, as functions of the stub length, to compute the circuit element values for these discontinuities     

场路结合法分析设备电磁辐照效应

电子设备机壳内部往往会内置多层印制电路板,外界电磁干扰很可能通过设备的外接导线进入设备内部进而对电路板造成损坏。针对这种情况,采用全波分析法获得受干扰设备的相关参数,利用该参数建立等效源模型;等效电路法分析内部电路板上电路的电磁特性。通过全波分析法和等效电路法相结合的方式来分析外界电磁干扰进入设备内部时所造成的影响,为处于高频电磁干扰环境中的电路工作特性研究提供新思路和参考。     

FET-integrated CPW and the application in filter synthesis design method on traveling-wave switch above 100 GHz

A new transmission-line concept, called the field-effect transistor (FET)-integrated coplanar waveguide (CPW), is proposed. This concept treats the passive two-finger FET as CPW and, thus, the scaling rule is more accurate than the previous model, especially in high frequency. The extraction approach of the parameters of the FET-integrated CPW is also included. With this concept, the design procedure of traveling-wave switches can be equivalent to a filter synthesis problem. Based on this design procedure, a single-pole single-throw and a single-pole double-throw traveling-wave switch have been realized and measured using 0.15-/spl mu/m high-linearity AlGaAs/InGaAs/GaAs pseudomorphic high electron-mobility transistors. Finally, the frequency limitation of the traveling-wave switches is also discussed. The results show the FET-integrated CPW is the most efficient way to overcome the frequency limitations of traveling-wave switches, achieving operation frequency to 135 GHz, the highest frequency reported to date.