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 extraction of an empirical temperature-dependent InGaP/GaAs HBT large-signal model

A new empirical InGaP/GaAs heterojunction bipolar transistor (HBT) large-signal model including self-heating effects is presented. The model accounts for the inherent temperature dependence of the device characteristics due to ambient-temperature variation as well as self-heating. The model is accompanied by a simple extraction process, which requires only dc current-voltage (I-V) and multibias-point small-signal S-parameter measurements. All the current-source model parameters, including the self-heating parameters, are directly extracted from measured forward I-V data at different ambient temperatures. The distributed base-collector capacitance and base resistance are extracted from measured S-parameters using a new technique. The extraction procedure is fast, accurate, and inherently minimizes the average squared-error between measured and modeled data, thereby eliminating the need for further optimization following parameter extraction. This modeling methodology is successfully applied to predict the dc, small-signal S-parameter, and output fundamental and harmonic power characteristics of an InGaP/GaAs HBT, over a wide range of temperatures.     

DC to high-frequency HBT-model parameter evaluation using impedanceblock conditioned optimization

A new heterojunction bipolar transistor (HBT) small-signal equivalent-circuit parameter-extraction procedure employing multibias S-parameter data is presented. The algorithm combines analytical and empirical parameter evaluation techniques and results in a bias-dependent HBT model. To minimize the risk of nonphysical parameter estimation, elements such as the DC transport factor, α_o, and the emitter-base conductance are evaluated from the device DC characteristics, and the frequency dispersion of α is related to the RC time-constant of the emitter-base junction. Moreover, initial values for the extrinsic device parasitics are obtained from “hot” as well as “cold” S-parameter data. The method results in excellent fit between measured and modeled S-parameter data in the frequency range DC-40 GHz and for a wide range of bias operating points     

Determination and assessment of the floating-body voltage of SOICMOS devices

A self-consistent method to extract the off-state floating-body (FB) voltage of SOI CMOS devices is presented. The technique is simple and is based on CV and S-parameter measurements of a single standard SOI MOSFET device; no special test structure design is needed. The bias dependent S-parameter measurements of the FB SOI device and its equivalent circuit, along with the CV measurements between the drain and source of the same device, are used to determine the FB voltage. The technique provides reasonable insight on device off-state and leakage performances that are important for digital applications. Additionally, it proposes a method for the extraction of the parasitic source, drain, and gate resistances. Using the technique, FB voltage in excess of 0.4 V is measured in a partially depleted (PD) NMOS device at drain voltage of 2.5 V and zero gate voltage, demonstrating the importance of understanding FB effects on device off-state and junction leakage performances     

Extraction of the parameters of equivalent circuits of microwavetransistors using tree annealing

The problem of extracting a physically based equivalent circuit model for a heterostructure bipolar transistor (HBT) from S-parameter measurements is solved with a new formulation of simulated annealing. The physical model necessary for an accurate representation of the HBT leads to an extraction problem with many local minima. A satisfactory minimum can be found by conventional gradient-based techniques only with considerable expert guidance. The proposed algorithm finds equivalent circuits as good as those from conventional techniques but without human intervention. It is more efficient than conventional stochastic simulated annealing because it accumulates a probability density of good equivalent circuits which it subsequently uses to refine its statistical search for the best equivalent circuit     

微波功率器件大信号S参数的提取

介绍了微波有源器件大信号模型的计算机模拟技术和利用商品化软件ＨＰＭＤＳ提取大信号Ｓ参数的方法。     

Probe-tone S-parameter measurements

The measurement of device behavior under complex actual operating conditions is an increasingly important measurement problem. In particular, it can be difficult to accurately measure gain and some reflection coefficients of a power amplifier operating under a realistic modulated signal drive. A small-signal measurement alone of a power amplifier is generally incorrect since the device-under-test will not be biased correctly. A fully modulated measurement, however, may require very dedicated equipment, long measurement times for adequate stability, and special calibration techniques. The methodology discussed here, i.e., the use of S-parameter probe signals in addition to power signals, will allow self-consistent S-parameter measurement under these conditions with full (traceable) vector calibrations and reduced uncertainties. In some sense, the small probe signal is used to quantify nonlinearities introduced by the modulated signal. In addition, the measurement has the flexibility to perform frequency-domain profiling to elucidate the behavior that may be experienced by interfering signals     

A new small-signal modeling approach applied to GaN devices

A new small-signal modeling approach applied to GaN-based devices is presented. In this approach, a new method for extracting the parasitic elements of the GaN device is developed. This method is based on two steps, which are: 1) using cold S-parameter measurements, high-quality starting values for the extrinsic parameters that would place the extraction close to the global minimum of the objective function for the distributed equivalent circuit model are generated and 2) the optimal model parameter values are searched through optimization using the starting values already obtained. The bias-dependent intrinsic parameter extraction procedure is improved for optimal extraction. The validity of the developed modeling approach and the proposed small-signal model is verified by comparing the simulated wide-band small-signal S-parameter, over a wide bias range, with measured data of a 0.5-/spl mu/m GaN high electron-mobility transistor with a 2/spl times/50 /spl mu/m gatewidth.     

A simple method to determine the floating-body voltage of SOI CMOSdevices

A technique to extract the off-state floating-body (FB) voltage of silicon-on-insulator (SOI) CMOS devices is presented. The bias dependent S-parameter measurements of a single standard FB SOI device and its equivalent circuit, along with the capacitance-voltage (C-V) measurements between the drain and source of the same device, are used to determine the FB voltage. No special test structure design is needed. The technique proposes a method for the extraction of the parasitic source, drain, and gate resistances. Using the technique, FB voltage in excess of 0.4 V is measured in a partially depicted (PD) NMOS device at drain voltage of 2.5 V and zero gate voltage     

一种新的HBT小信号模型参数优化提取法

阐述了一种新的异质结双极型晶体管（HBT）的小信号模型参数提取方法――综合多偏置点优化参数提取法. 对HBT小信号模型进行推导并确定外部参数和内部参数的计算公式;介绍了多偏置点优化算法,并在GaInP/ GaAs HBT器件上进行了鲁棒性和精确性测试. 实验采用了一系列随机初始值,结果表明提取的参数值具有唯一收敛性和精确性,仿真结果与测量数据的相对误差小于1%.     

100 GHz active electronic probe for on-wafer S-parameter measurements

Reports the development of an active electronic probe for 100 GHz on-wafer S-parameter measurements. Integrated on the substrate of this wafer probe were a quintupler for 100 GHz stimulus signal generation, two directional couplers for incident and reflected signals sampling, and two newly developed harmonic mixers to down-convert these 100 GHz signals to 20 MHz. The authors also demonstrate all-electronic on-wafer 75-100 GHz two-port S-parameter measurements using these probes.<>     

Design and performance of a noncontacting probe for measurements onhigh-frequency planar circuits

Optimal design of a noncontacting magnetic probe for measurements on the interior of planar high-frequency circuits has been studied, and performance of the probe has been determined. The design was studied using enlarged models tested at frequencies 100 times lower than those of the actual intended use. The nature of its errors has been investigated, and some techniques for error reduction have been found. The accuracy of measurements on circuits with SWR <3.0 is typically 0.8 dB in magnitude and 7° in phase. S-parameter measurements on general two-ports can also be made by using the probe at several different positions on the associated transmission lines. The technique effectively eliminates the problem of de-embedding that arises in other kinds of S-parameter measurements. Examples of measurements with the large model probe are presented and compared with theory. Performance appears to be acceptable for the intended applications     

A self-consistent method for complete small-signal parameterextraction of InP-based heterojunction bipolar transistors (HBT's)

A complete method for parameter extraction from small-signal measurements of InP-based heterojunction bipolar transistors (HBT's) is presented. Employing analytically derived equations, a numerical solution is sought for the best fit between the model and the measured data. Through parasitics extraction and an optimization process, a realistic model for a self-aligned HBT technology is obtained. The results of the generated s-parameters from the model for a 2×10 μm² emitter area device are presented over a frequency range of 250 MHz-36 GHz with excellent agreement to the measured data     

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%     

A three-step method for the de-embedding of high-frequencyS-parameter measurements

The authors propose a general method of deembedding S-parameter measurements of the device-under-test (DUT) for which typical parasitics associated with probe pads and interconnect-metal lines can be deembedded from the measurement. The DUT is the analog silicon bipolar junction transistor including the pad and interconnects. This method includes the subtraction of the parasitic shunt y-parameters of the on-wafer open calibration pattern as well as the subtraction of the parasitic series z-parameters on the on-wafer open circuit which are taken from measurements of the short and through circuits. It is demonstrated that the calculated power loss for the pad and interconnect parasitics can be comparable to the power consumption of the advanced bipolar transistor at high frequencies (⩾10 GHz). A knowledge of the magnitude and type of parasitic deembedding circuit elements can aid the device engineer in the analysis of the error associated with deembedding     

The DC characteristics of GaAs/AlGaAs heterojunction bipolartransistors with application to device modeling

A complete DC model for the heterojunction bipolar transistor (HBT) is presented. The DC characteristics of the HBT are compared with the Ebers-Moll (EM) model used by conventional bipolar junction transistors (BJTs) and implemented in simulation and modeling programs. It is shown that although the details of HBT operation can differ markedly from those of a BJT, a model and a parameter extraction technique can be developed which have physical meaning and are exactly compatible with the EM models widely used for BJTs. Device I- V measurements at 77 and 300 K are used to analyze the HBT physical device performance in the context of an EM model. A technique is developed to extract the device base, emitter, and collector series resistances directly from the measured I-V data without requiring an ideal exp(qV_be/kT) base current as reference. Accuracies of the extracted series resistances are assessed. AC parameters of HBT are calculated numerically from the physical device structure. For modeling purposes, these parameters are shown to be comparable with those of conventional BJTs     

SiGe HBT非准静态小信号等效电路的参数提取

提出了一种硅锗异质结双极型晶体管（SiGe HBT）非准静态效应的小信号等效电路模型的参数提取方法。整个参数提取过程建立在由非准态效应的小信号等效电路推导出的一系列泰勒级数解析公式并结合参数直接法,该方法依赖于测量的S参数,不使用任何的数值优化法,参数提取结果使用CAD仿真验证。结果表明该参数提取方法简单易行,较为精确,该方法能够用到不同工艺SiGe HBT参数提取。     

Modulated S-parameter measurements for isothermal microwave devicecharacterization

The validity of extracted microwave device models is critically dependent on the completeness, accuracy, and appropriateness of the starting device characterization data. In this letter we will present a novel technique for determining the S-parameters of a device under isothermal (i.e., no heating) operation. Additionally, this technique can be applied to determining the CW S-parameters under more extreme (e.g., forward bias/breakdown) operation. By pulse-biasing the device from the “OFF” to the “ON” state, while performing standard S-parameter measurements, resultant data is found to be characteristic of the weighted (by duty factor) scalar sum of the devices “ON”-state and “OFF”-state S-parameter(s). We will show how these measurements can then be used to interpret the devices isothermal CW S-parameters     

An accurate on-wafer deembedding technique with application to HBTdevices characterization

An accurate deembedding technique for on-wafer measurements of an active device's S-parameter is presented in this paper. This deembedding technique accounts in a systematic way for effect of all parasitic elements surrounding the device. These parasitic elements are modeled as a four-port network. Closed-form equations are derived for deembedding purposes of this four-port network. The proposed deembedding technique was used to extract small-signal model parameters of a 2×25 μm emitter GaInP/GaAs heterojunction bipolar transistor device, and excellent agreement between measured and model-simulated S-parameter was obtained up to 30 GHz     

Millimeter-wave FET modeling using on-wafer measurements and EMsimulation

Electron device modeling is a challenging task at millimeter-wave frequencies. In particular, conventional approaches based on lumped equivalent circuits become inappropriate to describe complex distributed and coupling effects, which may strongly affect the transistor performance. In this paper, an empirical distributed FET model is adopted that can be identified on the basis of conventional S-parameter measurements and electromagnetic simulations of the device layout. The consistency of the proposed approach is confirmed by robust scaling properties, which enable millimeter-wave small-signal S-parameters to be predicted as a function of the device periphery and number of gate fingers. Moreover, it is shown how the model identified on the basis of standard S-parameter measurements up to 50 GHz can be efficiently exploited in order to obtain reasonably accurate small-signal prediction up to 110 GHz. Extensive experimental validation is presented for 0.2-μm pseudomorphic high electron-mobility transistors devices