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ABSTRACT: This paper introduces a procedure for extracting a two-input two-output nonlinear behavioral model for band-pass microwave power amplifiers, based on linearized large-signal vector measurements. The proposed method consists in integrating the time-varying linear characterization of the PA, driven into a nonlinear state by a large signal. The experiment design and the measurement set-up are enabled by the unique features of a mixer-based large-signal network analyzer. An extensive, independent, experimental validation considered a 950 MHz PA prototype fabricated with surface mount components assembled in microstrip technology on a FR4 as a case study. The experimental results include large-signal gain, harmonics generation, large-signal outputinput reflections at carrier, WCDMA envelope signal test and S-parameters.
Microwave Symposium Digest, 2009. MTT '09. IEEE MTT-S International; 07/2009
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ABSTRACT: 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.
IEEE Transactions on Microwave Theory and Techniques 12/2007; · 1.85 Impact Factor
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ABSTRACT: This paper introduces a model for dynamic nonlinear microwave systems or device operating in large signal regime, based on a state-space formulation. It differs from previous approaches in the comprehensive description of the describing functions and the identification procedure based on the solution of a linear system of equations. The model is able to predict specific operation states, having identified the model in an a-priory defined set of operation states. The identification procedure, as well as the validation, is based on multisine large signal time domain measurements at different input power levels. Extensive experimental results are provided for a case study based on a commercial InGaP HBT gain block driven by a set of 9 tones equally distributed in 1.6 MHz bandwidth around the frequency of 4.9GHz, with all the power levels ranging from linear to saturation regions. The accuracy of the model, also in terms of prediction capabilities is provided in both time- and frequency-domain.
Microwave Symposium Digest, 2005 IEEE MTT-S International; 07/2005
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ABSTRACT: The paper proposes an approach to model a P-HEMT taking into account for the electrical-thermal- electromagnetic behavior in an effective way.The model is based on the integration of a distributed approach,which considers an intrinsic device for gate finger,each of them equipped with a thermal equivalent circuit.The latter considers also the mutual interacting between the adjacent intrinsic devices by means a voltage-controlled voltage- source that allows considering the thermal coupling by a series of coefficients determined in an analytical way.The electrical model has been extracted from a 2x150um PHEMT and then applied to predict the DC and RF characteristic of a 8x150um proving the model scalability capability.
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ABSTRACT: This paper deals with the identification of
equivalent circuit models for strongly nonlinear devices by
taking advantage of the so-called “Vectorial Large-Signal
Measurements”. A very specific device, the Heterojunction
Interband Tunneling FET (HITFET), has been selected as
case of study for its peculiar nonlinear behavior. A
comprehensive description of the identification is given
along with a number of experimental results. In
particular, the comparison between simulated and
measured data for different power levels and frequencies
from the set adopted during the identification confirms the
extrapolation capability of the approach.
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ABSTRACT: This paper introduces experimental observations
and theoretical considerations on a newly introduced technique allowing to measure the admittance conversion matrix of microwave device, by large-signal vectorial measurements.
In particular, it discusses the capability and the limitation of the method to evaluate the conversion matrix of an anti-parallel Schottky diode-pair, starting from the measurement of the single diode.
A theoretical treatment and several simulated and
experimental results give an insight into the approach.
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ABSTRACT: This paper presents a comprehensive
treatment of the nonlinear electro-thermal memory
effect arising in a GaAs PHEMT. In particular is
demonstrated the way with which the pure nonlinear
electrical effect and the electro-thermal one combine
and in turn determine a dispersive third-order
intermodulation. The analysis is based on an accurate
distributed model modified in order to take into
account for the dynamic thermal behaviour under
large signal operation. The results show a reduction
of the intermodulation product in response to a
reduction of the two tones frequency spacing, in
agreement with the analytical treatment.
