Parameter extraction technique for HBT equivalent circuit usingcutoff mode measurement

A parameter extraction method based on the S-parameter measurements of the heterojunction bipolar transistors (HBTs) biased to cutoff is proposed. This method is applied to confirm the results for the RF probe pad and interconnection pattern parasitics obtained from the special test structures, and to determine some of the device capacitances of the HBT. The remaining device parameters are extracted by the S-parameter measurements of the devices biased to the active mode. The extraction technique gives good agreement between the equivalent circuit and the measured S-parameters of the HBT including probe pads and interconnections     

New circuit model for RF probe pads and interconnections for theextraction of HBT equivalent circuits

A new circuit model for RF probe pads and interconnections is proposed, and this model and previous models are compared with measured S parameters of probe pad and interconnection test structures. A modified parameter and interconnnection model was used to determine an HBT equivalent circuit. Excellent agreement is obtained between the extracted equivalent circuit and measured HBT S parameters, while providing physically acceptable parameter values     

Analytical parameter extraction of the HBT equivalent circuit withT-like topology from measured S-parameters

A pure analytical method for extraction of the small-signal equivalent circuit parameters from measured data is presented and successfully applied to heterojunction bipolar transistors (HBT's). The T-like equivalent circuit is cut into three shells accounting for the connection, and the extrinsic and intrinsic parts of the transistor. The equivalent circuit elements are evaluated in a straightforward manner from impedance and admittance representation of the measured S-parameters. The measured data are stripped during the extraction process yielding, step by step, a full set of circuit elements without using fit methods. No additional knowledge of the transistor is needed to start the extraction process with its self-consistent iteration loop for the connection shell. The extrinsic and intrinsic equivalent circuit elements are evaluated using their bias and frequency dependencies. This method yields a deviation of less then 4% between measured and modeled S-parameters     

A parameter extraction method using cutoff measurement for alarge-scale HSPICE model of HBT's

We present an accurate parameter extraction method for the HBT large-signal equivalent circuit model in which several extrinsic parasitics are connected to HSPICE BJT model. The measured Gummel plot are used to extract DC model parameters of HBT using HSPICE. Capacitances are then obtained from S-parameter measurements of the HBTs biased to cutoff. The other parameters are determined from the active device S-parameters. The large-signal modeled Gummel plot and S-parameters show good agreement with the measured ones, respectively     

Direct parameter-extraction method for HBT small-signal model

An accurate and broadband method for the direct extraction of heterojunction bipolar transistor (HBT) small-signal model parameters is presented in this paper. This method differs from previous ones by extracting the equivalent-circuit parameters without using special test structures or global numerical optimization techniques. The main advantage of this method is that a unique and physically meaningful set of intrinsic parameters is extracted from the measured S-parameters for the whole frequency range of operation. The extraction procedure uses a set of closed-form expressions derived without any approximation. An equivalent circuit for the HBT under a forward-bias condition is proposed for extraction of access resistances and parasitic inductances. An experimental validation on a GaInP/GaAs HBT device with a 2×25 μm emitter was carried out, and excellent results were obtained up to 30 GHz. The calculated data-fitting residual error for three different bias points over 1-30 GHz was less then 2%     

Extraction of Passive Device Model Parameters Using Genetic Algorithms

The extraction of model parameters for embedded passive components is crucial for designing and characterizing the performance of multichip module (MCM) substrates. In this paper, a method for optimizing the extraction of these parameters using genetic algorithms is presented. The results of this method are compared with optimization using the Levenberg‐Marquardt (LM) algorithm used in the HSPICE circuit modeling tool. A set of integrated resistor structures are fabricated, and their scattering parameters are measured for a range of frequencies from 45 MHz to 5 GHz. Optimal equivalent circuit models for these structures are derived from the s‐parameter measurements using each algorithm. Predicted s‐parameters for the optimized equivalent circuit are then obtained from HSPICE. The difference between the measured and predicted s‐parameters in the frequency range of interest is used as a measure of the accuracy of the two optimization algorithms. It is determined that the LM method is extremely dependent upon the initial starting point of the parameter search and is thus prone to become trapped in local minima. This drawback is alleviated and the accuracy of the parameter values obtained is improved using genetic algorithms.     

Fast and efficient extraction of HBT model parameters usingmultibias S-parameter sets

Accurate parameter extraction technique has been presented for a small-signal equivalent circuit model of AlGaAs-GaAs HBT's. This technique makes use of multibias data optimization regarding two sets of S-parameters in the active mode and one in the cut-off mode, under the physics-based constraint that current-dependent elements in two active bias circuits are linked to each other by the ratio of their currents. This multibias optimization as well as the constraint imposed on intrinsic parameters may reduce the degree of freedom of circuit variables and increase the probability of finding a global minimum result. As a result of this extraction, good agreement is seen between the circuit models and their measured S-parameters in the frequency range of 0.045 to 26.5 GHz     

A pure analytic method for direct extraction of collector-up HBT's small-signal parameters

A pure analytic procedure for direct extraction of the small-signal equivalent-circuit parameters, including extrinsic inductances, has been demonstrated and successfully applied to III-V and SiGe collector-up heterojunction bipolar transistors (HBTs). This method can alleviate some difficulties encountered among conventional extracting techniques that are the use of additional test structures, forward-biased measurements at specific bias conditions, and empirical optimization process. In this paper, the hybrid-/spl pi/ equivalent-circuit elements are extracted in a simple and efficient way from impedance and admittance formulation on the basis of measured S-parameters. To study the bias dependence, the extrinsic and intrinsic circuit components are evaluated under different bias conditions. The model parameters are sequentially derived during the extraction process yielding a full set of physical element values. The validity of our model is explored on pnp collector-up AlGaAs-InGaAs HBTs, and a good coincidence between measured and modeled S-parameters is observed for the entire frequency range of operation. Consistent extracted trends indicate that this improved equivalent-circuit model is suitable to be implemented in circuit simulators for microwave-circuit TCAD applications.     

An approach to determine small-signal model parameters for InP-based heterojunction bipolar transistors

A new method for the extraction of the small-signal model parameters of InP-based heterojunction bipolar transistors (HBT) is proposed. The approach is based on the combination of the analytical and optimization technology. The initial values of the parasitic pad capacitances are extracted by using a set of closed-form expressions derived from cutoff mode S-parameters without any test structure, and the intrinsic elements determined by using the analytical method are described as functions of the parasitic elements. An advanced design system is then used to optimize only the parasitic parameters with very small dispersion of initial values. Good agreement is obtained between simulated and measured results for an InP HBT with 5/spl times/5 /spl mu/m/sup 2/ emitter area over a wide range of bias points up to 40 GHz.     

Small-signal model parameter extraction of E-mode N-polar GaN MOS-HEMT using optimization algorithms and its comparison

An improved small-signal parameter extraction technique for short channel enhancement-mode N-polar GaN MOS-HEMT is proposed,which is a combination of a conventional analytical method and optimization techniques.The extrinsic parameters such as parasitic capacitance,inductance and resistance are extracted under the pinch-off condition.The intrinsic parameters of the small-signal equivalent circuit (SSEC) have been extracted including gate forward and backward conductance.Different optimization algorithms such as PSO,Quasi Newton and Firefly optimization algorithm is applied to the extracted parameters to minimize the error between modeled and measured S-parameters.The different optimized SSEC models have been validated by comparing the S-parameters and unity current-gain with TCAD simulations and available experimental data from the literature.It is observed that the Firefly algorithm based optimization approach accurately extracts the small-signal model parameters as compared to other optimization algorithm techniques with a minimum error percentage of 1.3％.     

Very high-frequency small-signal equivalent circuit for shortgate-length InP HEMTs

A small-signal equivalent circuit for short gate-length InP high electron-mobility transistors (HEMTs) operating at very high frequency (HF) is proposed. First, the extrinsic parameters of the equivalent circuit are determined using a cold HEMT, but without forward gate bias. Then the intrinsic parameters of the equivalent circuit are extracted, including the frequency dependence of some of them. A fast and accurate method based on least-squares regressions is presented to obtain the extrinsic and intrinsic parameters from measured S-parameters. The improved equivalent circuit accurately fits the S-parameters of 0.25-μm InP HEMTs over the 500-MHz up to 40-GHz measurement bandwidth, for all gate-to-source and drain-to-source voltages     

射频CMOS平面螺旋电感2-π等效电路模型参数的提取

从有理分式拟合方法出发,提出了用于射频CMOS平面螺旋电感2-π等效电路模型参数提取的新方法.通过比较提参后等效电路给出的S参数和实验测量的S参数,证明该方法的精度很高.此外,提参的策略非常直接,因此容易在CAD里面编程实现.提参得到的等效电路模型对于射频电路设计者来说也是非常有用的.     

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。     

A simple parameter extraction method of spiral on-chip inductors

Accurate measurement and parameter extraction for spiral inductors are very important in monolithic microwave integrated circuit (MMIC) design. In this paper, we have proposed an easy and simple model parameter extraction method of wide-band on-chip inductor. The simple extraction methodology is applied to extract parameters from the measured S-parameters of spiral inductors fabricated with 0.18-/spl mu/m CMOS technology. Model prediction shows excellent agreement with the measured data over a wide frequency region. Also, the model can be easily integrated in SPICE-compatible simulators because all the elements are frequency independent. This method will provide practical and useful circuit parameters for MMIC design.     

一种基于半分析法的HEMT小信号参数的提取方法

提出了一种基于半分析法的高速电子迁移率半导体晶体管小信号模型的提取方法.此方法是用测试结构的方法来提取焊盘电容和寄生电感,半分析法来提取寄生电阻,提高了寄生电阻的提取精度.在频率高达40 GHz的范围内,多偏置情况下模拟的S参数和测试的S参数曲线吻合良好,证明这种方法是正确的.     

通过TRL校准提取管芯S参数的技术

介绍了一种基于TRL法的提取管芯S参数的方法.该方法从TRL校准出发,实际测量得到封装器件的S参数;管芯以外的参量(管壳及键和线)用等效电路表示,最后用微波仿真软件模拟得到管芯S参数.此方法在没有精确的测试夹具条件下,仍可以得到较理想的器件和管芯S参数.实验证明该方法简便、实用性强,可推广应用于不宜直接测量管芯S参数的器件.     

A new method to determine the source resistance of FET frommeasured S-parameters under active-bias conditions

A new method is proposed to evaluate the source resistance R_S directly from the S-parameters of a field-effect transistor biased in the active region. The method is based on the fact that the real part of the feedback admittance is mainly caused by the source and the gate resistance. This enables the analytical calculation of R_S at any measured frequency with high accuracy. Taking the ratio of R_G with regard to R_S as the only optimizing parameter, it is possible to calculate quickly an equivalent circuit the elements of which do not depend on starting values. The equivalent circuit fits the measured S-parameters very well and allows a physical interpretation of the calculated elements. By application of the new method in accordance with theoretical considerations one can observe for the first time from RF-measurements a bias-dependence of the source resistance that has been assumed to be constant up to now     

A novel transmission line characterisation based on measurement data reconfirmation

Due to inherent resonance effects and frequency-variant dielectric properties, it is very difficult to experimentally determine the stable and accurate circuit model parameters of thin film transmission line structures over a broad frequency band. In this article, a new, simple and straightforward frequency-variant transmission line circuit model parameter determination method is presented. Experimental test patterns for high-frequency transmission line characterisations are designed and fabricated using a package process. The S-parameters for the test patterns are measured using a vector network analyzer (VNA) from 100 MHz to 26.5 GHz. The parasitic effects due to contact pads are de-embedded. The frequency-variant complex permittivity and resonance-effect-free transmission line parameters (i.e., the propagation constant and characteristic impedance) are then determined in a broad frequency band.     

增强型InGaP/AlGaAs/InGaAs PHEMT小信号等效电路参数的提取

介绍了增强型InGaP/AlGaAs/InGaAs PHEMT小信号等效电路中元件参数值的提取方法,并利用IC-CAP软件EEHEMT1模型提取了参数.利用ADS软件验证了提参结果,ADS仿真的直流I-V曲线和S参数与实测结果基本吻合.结果表明EEHEMT1模型可以用于提取增强型PHEMT参数,并且具有可操作性.     

增强型InGaP/AlGaAs/InGaAs PHEMT小信号等效电路参数的提取

介绍了增强型InGaP／AlGaAs／InGaAs PHEMT小信号等效电路中元件参数值的提取方法，并利用IC-CAP软件EEHEMT1模型提取了参数．利用ADS软件验证了提参结果，ADS仿真的直流I-V曲线和S参数与实测结果基本吻合．结果表明EEHEMT1模型可以用于提取增强型PHEMT参数，并且具有可操作性．