Large Signal Network Analyzer Research Articles

Empirical global modelling of Si/SiGe heterojunction bipolar transistors

A simple and straightforward extraction procedure for a global model of silicon/silicon-germanium (Si/SiGe) heterojunction bipolar transistors (HBTs) is presented. The model has been constructed using functions that describe the dependence of the most nonlinear extracted small-signal equivalent circuit model (SSECM) parameters on the terminal voltages. The other model parameters are assumed to be voltage independent. An artificial neural network fitting tool has been used to obtain these relations. The model has been implemented in a software package without any convergence problems and has been evaluated by direct current, small-signal and large-signal network analyser measurements. An excellent correspondence has been obtained between the measurements and the output of the simulations for the extracted model. Because of its high accuracy, the model is very efficient in radio frequency circuit design. To the author's knowledge, this is the first time that a global model for a Si/SiGe HBT has been derived directly from a SSECM.

Time-Domain Calibrated Measurements of Wideband Multisines Using a Large-Signal Network Analyzer

This paper presents a calibrated measurement technique that enables phase and magnitude measurements of wideband multisines. This study is based on the use of a large-signal network analyzer (LSNA) performing harmonic sub-sampling and a fine frequency grid (20 MHz) comb generator calibrated using a high-frequency 50-GHz equivalent-time sampling scope. This comb generator is used as a harmonic phase reference generator for the calibration of the LSNA. The research reported here is applied to L-band multisine measurements, but it can be extended to higher microwave frequencies. The motivation of this study is to measure the multipactor phenomena effect in output RF multiplexers of satellite payloads.

High Efficiency RF Power Amplifier Designed With Harmonic Real-Time Active Load-Pull

In this work, a high efficiency p-HEMT radio frequency power amplifier (PA) is designed using a new multiharmonic real-time active load-pull using the large signal network analyzer. This technique synthesizes a large set of instantaneous load mismatches to quickly find the optimal harmonic impedances, so as to achieve high PA efficiency in a shortened design cycle. At 2 GHz a demo power amplifier implemented with a p-HEMT demonstrated a power added efficiency (PAE) of 68.5% for 18.0 dBm output power, while achieving a maximum PAE of 75% below the 1 dB compression point for 18.6 dBm output power.

Accurate and robust estimation of phase error and its uncertainty of 50 GHz bandwidth sampling circuit

This paper discusses the dependence of the phase error on the 50 GHz bandwidth oscilloscope’s sampling circuitry. We give the definition of the phase error as the difference between the impulse responses of the NTN (nose-to-nose) estimate and the true response of the sampling circuit. We develop a method to predict the NTN phase response arising from the internal sampling circuitry of the oscilloscope. For the default sampling-circuit configuration that we examine, our phase error is approximately 7.03° at 50 GHz. We study the sensitivity of the oscilloscope’s phase response to parametric changes in sampling-circuit component values. We develop procedures to quantify the sensitivity of the phase error to each component and to a combination of components that depend on the fractional uncertainty in each of the model parameters as the same value, ±10%. We predict the upper and lower bounds of phase error, that is, we vary all of the circuit parameters simultaneously in such a way as to increase the phase error, and then vary all of the circuit parameters to decrease the phase error. Based on Type B evaluation, this method qualifies the impresses of all parameters of the sampling circuit and gives the value of standard uncertainty, 1.34°. This result is developed at the first time and has important practical uses. It can be used for phase calibration in the 50 GHz band-width large signal network analyzers (LSNAs).

An Electrothermal Model for AlGaN/GaN Power HEMTs Including Trapping Effects to Improve Large-Signal Simulation Results on High VSWR

A large-signal electrothermal model for AlGaN/GaN HEMTs including gate and drain related trapping effects is proposed here. This nonlinear model is well formulated to preserve convergence capabilities and simulation times. Extensive measurements have demonstrated the impact of trapping effects on the shapes of I(V) characteristics, as well as load cycles. It is shown that accurate modeling of gate-and drain-lag effects dramatically improves the large-signal simulation results. This is particularly true when the output loads deviate from the optimum matching conditions corresponding to real-world simulations. This new model and its modeling approach are presented here. Large-signal simulation results are then reported and compared to load-pull and large-signal network analyzer measurements for several load impedances at high voltage standing wave ratio and at two frequencies.

Analytical extraction of small and large signal models for FinFET varactors

In this work we report on the small and large signal behaviour of advanced nMOS varactors fabricated in FinFET technology. This is the first paper showing large signal network analyzer (LSNA) measurements performed on FinFET varactors. These nonlinear measurements are modeled with a lookup table based model that is constructed using an accurate multi-bias small signal equivalent circuit. The validity of the extracted small and large signal models is verified through the very good agreement between measurements and simulations.

Mildly Nonquasi-Static Two-Port Device Model Extraction by Integrating Linearized Large-Signal Vector Measurements

This paper introduces a new procedure, based on linearized large-signal vector measurements, for extracting a nonlinear behavioral model for two-port active microwave devices. The technique is applied to a model structure that assumes a short-term memory condition and is formulated as a parallel connection of a limited number of frequency-weighted static nonlinearities. The proposed method consists of integrating the time-varying linear characterization of the device driven into a nonlinear state by a large signal. The experiment design and measurement setup are based on a large-signal network analyzer and are discussed in detail. In the second portion of this paper, insight is provided on the most meaningful model parameters, along with an extensive independent experimental validation, which considers a GaAs pHEMT as a case study and includes two-tone large-signal data, a wideband code division multiple access signal, bias-dependent -parameters, and dc data.

Identifying the Structure of Nonlinear Perturbations in Mixers using Multisine Signals

The objective of this paper is to identify the position of the nonlinearity, a custom designed multisine signal that can be used to excite the signal path of the mixer. This special random-phase multisine signal with a random harmonic grid contains several carefully selected spectral lines that are left unexcited. These "holes" in the spectrum of the signal act as detectors for the presence and the location of the nonlinearities that deviate from the ideal. First the proposed detection algorithm was tested in a simulation to show that it can work in an ideally controlled environment. Afterwards, measurements are performed on a real mixer excited with a special odd random-phase multisine with a two-port large signal network analyzer (LSNA) and detect the position of the unwanted nonlinearities in the device model.

Determining the Reciprocity of Mixers Through Three-Port Large Signal Network Analyzer Measurements

In this paper, a method to determine the reciprocity of radio-frequency mixers is proposed based on fully calibrated three-port large signal network analyzer measurements. Besides revealing the reciprocity of the mixers, this type of measurement can also be used in yielding the match conditions at all ports as well as magnitude, phase, and group-delay response of the conversion loss of the mixer.

Time‐dependent characterization of an optically modulated CPW line characterized with a large signal network analyzer

AbstractTime‐dependent behavior of a CPW line under optical modulation is characterized using a large‐signal vector network analyzer. The influence of the optical modulation frequency on the propagation of high carrier frequencies along a CPW is discussed in this article. Different operation conditions in time are defined for a CPW line under illumination. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3124–3128, 2007; Published online in Wiley Inter‐Science (www.interscience.wiley.com). DOI 10.1002/mop.22888

The MTT-II Web Page: A Multitude of Information Resources on Microwave Measurements [Member Benefits

106 August 2007 The Microwave Measurements Technical Committee of the MTTS (MTT-11) promotes activities related to microwave measurement technology and science. One of its main vehicles of information dissemination for general IEEE Members is its Web page interface (http://www.mtt.org/committees/mtt-11/index.html), which is a valuable tool for any microwave engineer who needs to be informed about measurements of radio, high-speed electrical, and microwave quantities. The Web page contains several important types of information for the IEEE community; for instance, a milestone paper Web page found here allows the reader to navigate through several important IEEE papers that are fundamental research works in the field and have revolutionized their area. Most of the referred papers have a direct link to IEEE Xplore (http:// ieeexplore.ieee.org), so that the reader can immediately download the paper from the net if he or she is an IEEE Member. This manner of presenting key technical material could reduce the time needed for research if the engineer is searching for a quick introduction to a given area. The Web page also has an area dedicated to the members of the committee. There it is possible to find contact information for the members, each of whom is considered an expert in his or her area. Thus, the reader can quickly find someone who could help with specific measurement issues on a given topic. This is further complemented by a page dedicated to our Speakers Bureau list, where the interested reader can learn about our appointed speakers and the talks they are presenting. At the time of this writing, MTT-11 has three speakers appointed: Dr. Jan Verspecht [Jan Verspecht bvba] and Prof. Andrea Ferrero [Politecnico di Torino], who are presenting a talk devoted to “Nonlinear Microwave Measurements: From Power Meters to Large-Signal Network Analyzers,” and Dr. Michael Janezic [NIST], whose talk is devoted to “HighFrequency Measurements of Dielectric Substrate Materials.” It is also possible to see and hear the talk of MTT Distinguished Microwave Lecturer [2004–2006] Doug Rytting related to “Calibration and Error Correction Techniques for Network Analysis.” This talk is now available to all net surfers in video streaming format. Other pages on the Web site lead us to the most important conferences worldwide devoted to microwave measurements, and we also have links devoted to international institutions related to measurements. Nuno Borges Carvalho is with the Universidade de Aveiro, Portugal. The MTT home page

</title> </titles> <publication_date> <month>06</month> <year>2007</year> </publication_date> <pages> <first_page>679</first_page> <last_page>680</last_page> </pages> <publisher_item> <item_number item_number_type='arNumber'>4200994</item_number> </publisher_item> <doi_data> <doi>10.1109/TIM.2007.895578</doi> <resource>http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=4200994</resource> </doi_data> </journal_article> <journal_article> <titles> <title><![CDATA[Measuring Nonlinear Differential RF Amplifiers Using One Single-Ended Source

A measurement procedure for the nonlinear baseband response of a differential amplifier is proposed using the large-signal network analyzer. The setup uses only one single-ended RF generator. A simplified nonparametric model for the frequency response of the device and its nonlinear contributions over a wide power range is proposed, measured, and validated experimentally

Determination and Validation of New Nonlinear FinFET Model Based on Lookup Tables

The Fin field effect transistor (FinFET) is a multiple gate structure, which is recently emerging as a leading structure to continue the scaling of CMOS technology into the nanometer regime. This promising multiple gate structure has not only the advantage of reducing short channel effects but also of being compatible with the conventional planar CMOS technology. To our knowledge, this is the first letter addressing the nonlinear FinFET model validated by large signal network analyzer measurements. Here, we present a nonlinear FinFET model which is based on lookup tables. The accuracy of the developed model is completely and successfully verified through the comparison with nonlinear FinFET measurements

Effective Suppression of IV Knee Walk-Out in AlGaN/GaN HEMTs for Pulsed-IV Pulsed-RF With a Large Signal Network Analyzer

IV knee walk-out in AlGaN/GaN high electron mobility transistors (HEMTs) on a Sapphire substrate is analyzed using dynamic radio frequency (RF) load-lines acquired with a large signal network analyzer (LSNA) for both continuous-wave (CW) and pulsed-IV/RF excitations. When thermal effects and traps are bypassed using pulsed-IV biasing and pulsed-RF excitations, the IV knee walk-out observed in CW load-lines is found to be effectively suppressed and the device delivers the maximum output power expected for class A operation. It is also demonstrated using pulsed-IV/RF measurements at various substrate temperatures that the IV knee walk-out primarily arises from thermal effects at high bias rather than trapping in the on-wafer devices characterized

A large-signal network analyzer: Why is it needed?

Good measurements are a major step towards good modeling. However, besides these measurements, modeling a system also requires a good insight in the system behavior. Do harmonics rise above the noise floor? Must they be taken into account during modeling? Is the system essentially dynamic or static? An answer to the above questions lies in the preprocessing of the measured data as obtained by the LSNA. This technique makes nonlinear effects more visible and allows understanding of the energy transport mechanisms behind the device operation

Phase-sensitive measurements of nonlinearity in high-temperature superconductor thin films

We present new frequency-dependent measurements of both the magnitude and phase of the nonlinear response in superconducting thin films at microwave frequencies obtained using a large-signal network analyzer. Our measurements show that the nonlinear inductance dominates the nonlinear response in thin YBCO films at 76 K, and our analysis yields two current-density scales corresponding to the real and imaginary components of the nonlinear response. The current-density scale associated with the dominant inductive response likely results from intrinsic pair-breaking, while the current-density scale associated with the nonlinear resistive term is smaller than the expected value due to pair-breaking, and could originate from vortex motion or other extrinsic effects.

Non‐linear performance comparison for FD and PD SOI MOSFETs based on the integral function method and Volterra modelling

AbstractThe harmonic and intermodulation distortions of both fully‐depleted (FD) and partially‐depleted (PD) silicon‐on‐insulator (SOI) MOSFETs are studied. The analysis is based on the recently developed integral function method and the results are compared to a third‐order Volterra model of the MOSFET. This modelling helps us to understand the non‐linear mechanisms of the considered devices and to predict their frequency behaviour. The models are validated through large‐signal network analyser measurements. The devices performances are discussed. Copyright © 2005 John Wiley & Sons, Ltd.

A time- and frequency-domain characterization of a thin-film metamorphic HEMT under modulated backside illumination

This article shows how the opto-electrical interaction of a microwave device, that is, a metamorphic HEMT, can be characterized by combining a large-signal network analyzer setup with a modulated laser (1550-nm) module. Furthermore, an optically tunable oscillator has been realized in multilayer thin-film technology. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14: 535–542, 2004.