Behavioral model analysis of active harmonic load-pull measurements

IEEE Trans. Microwave Theory Techn.

Zhu

et al. 2015

A new frequency-domain nonlinear behavioral modeling technique is presented and validated in this paper. This technique extends existing Padé and poly-harmonic distortion models by including the load reflection magnitude, , as a parameter. Although a rigorous approach requires a full 2-D load-pull model to cover the entire Smith chart, simulation and experimental evidence have shown that such a 1-D model-that retains only amplitude information of the load reflection coefficient-can give accuracy close to that of a full 2-D load-pull model. Consequently, neglecting the phase constitutes an approximation that provides large benefits without appearing to lead to a severe compromise in accuracy. Furthermore, compared with traditional load-independent models, the new -dependent models provide a major improvement in model accuracy. After a discussion of the model extraction methodology, examples are provided comparing traditional load-pull -parameter models with the model presented in this paper. The new model not only provides consistently good accuracy, but also has a much smaller model file size. Along with the examples that display the ability of the new modeling technique to predict fundamental frequency behavioral, a second harmonic example is also provided. The modeling approach is also validated using measurements results.

Section: Basic Theory Of -Dependent Modelsmentioning

confidence: 99%

Nonlinear Behavioral Modeling Dependent on Load Reflection Coefficient Magnitude

IEEE Trans. Microwave Theory Techn.

Zhu

et al. 2015

“…Many different modeling approaches have been pursued over the years; from behavioralbased methods to physics-based/semi-empirical models [7][8][9][10][11][12][13][14][15][16]. Physics-based models of RF components have been employed extensively in the RF world e.g.…”

Section: Introductionmentioning

confidence: 99%

Machine learning-based broadband GaN HEMT behavioral model applied to class-J power amplifier design

Int. J. Microw. Wireless Technol.

Chen

et al. 2020

A novel, broadband, nonlinear behavioral model, based on support vector regression (SVR) is presented in this paper. The proposed model, distinct from existing SVR-based models, incorporates frequency information into its formalism, allowing the model to perform accurate prediction across a wide frequency band. The basic theory of the proposed model, along with model implementation and the model extraction procedure for radio frequency transistor devices is provided. The model is verified through comparisons with the simulation of an equivalent circuit model, as well as experimental measurements of a 10 W Gallium Nitride (GaN) transistor. It is seen that the efficiency prediction throughout the Smith chart, for varying fundamental and second harmonic loads, across a wideband frequency range, show excellent fidelity to the measured results. Device dc self-biasing is also modelled to allow prediction of power amplifier (PA) efficiency, which is shown to be highly accurate when compared with corresponding measured data. Finally, a class-J PA is constructed and measured across the frequency with a large-signal input tone. The resulting measured and modelled values of key PA performance figures are shown to be in excellent agreement, indicating the model is suitable for broadband PA design.

“…The PHD method, 10 along with the similar S‐function method, 13 are two nonlinear modeling strategies, and it is convenient that corresponding innovations in RF measurement equipment enables direct extraction of such models with a high level of accuracy. The load‐pull X‐parameter model 14,15 as well as the work of Cardiff model 16‐18 has extended the PHD model to allow accuracy to be maintained under multiple large‐signal incident waves (rather than modeling just a single dominant input signal).…”

Section: Introductionmentioning

confidence: 99%

Large‐signal behavioral model for radio frequency power transistors based on modified canonical sectionwise piecewise‐linear functions

Int J Numerical Modelling

et al. 2020

A novel, large-signal behavioral modeling methodology for radio frequency power transistors, based on the modified canonical sectionwise piecewiselinear (CSWPL) functions, is presented in this article. The basic theory of the proposed model is provided. Compared with the existing standard CSWPL model, the proposed model provides superior prediction capabilities for a reasonable increase in model complexity. Model verification is performed through comparisons with simulated and experimental data of a 10 W GaN HEMT device at mild and severe mismatch conditions, across a wide range of input power levels. The models can predict, more accurately, both the fundamental and the second harmonic scattered waves compared with the standard CSWPL model.