Small-signal microwave measurements and modeling of GaN FET devices manufactured by ITME

© 2015, Kluwer Academic Publishers. All Rights Reserved. We present results of small-signal measurements and modeling of GaN FET devices  anufactured by Institute of Electronics Materials Technology (ITME). The devices have 500 nm gate length and 100 μm gate width and are grown on 350 μm sapphire substrate. We measured scattering parameters of the devices on-wafer in the frequency range 0.01-15 GHz, and then extracted parameters of their small-signal equivalent circuits. These results show that the devices have repeatable parameters and are capable of delivering at least 14.4 dB of unilateral gain in S-band with fmax of at least 23 GHz.status: publishe

Behavioral modeling of RF PAs under wideband load modulation

This work proposes a behavioral modeling approach suitable for power amplifier (PA) operation under dynamic load modulation. The model accounts for the PA nonlinear dynamic effects by means of 1st order kernel functions of the modified Volterra formulation, extracted from automated Nonlinear Vector Network Analyzer (NVNA) measurements. Validation experiments under wideband load modulation are reported for a commercial PA concurrently excited by an RF multi-tone at the input, and by another multi-tone actively injected at the output in order to generate a dynamic load. The experiment is performed at 2.4 GHz with 20 MHz bandwidth signals

Load-pull measurements using centroidal voronoi tessellation

International audienceIn this paper, we propose the Centroidal Voronoi Tessellation as a design of experiments for load-pull measurements. Contrary to other designs of experiments common in load-pull measurements, the Centroidal Voronoi Tessellation directly aims at the most uniform coverage of the input space of variables. This allows minimizing the mean and maximum distance from any point of the space to the closest sample, and as such, maximizing the information gain. The Centroidal Voronoi Tessellation is evaluated in the load-pull measurements of an amplifier. It is shown that employing Centroidal Voronoi Tessellation enables reaching higher model accuracies within less samples, which minimizes the total time of the load-pull measurements

A Two-Port Nonlinear Dynamic Behavioral Model of RF PAs Subject to Wideband Load Modulation

none6siThis work presents a full two-port, i.e., double input-double output, behavioral modeling approach suitable for radio frequency power amplifiers (PAs) in the presence of dynamic load modulation (DLM). The formulation of the model, based on a first-order approximation of a modified Volterra series, accounts for the nonlinear distortion determined by large-signal operation under mismatched conditions, and also for the memory effects stimulated by a modulated PA input signal, or by the dynamic variations of the PA load. By following an exhaustive procedure defined in the frequency domain, the model of a general purpose commercial PA is extracted over 160 MHz of modulation bandwidth (BW) with nonlinear vector network analyzer measurements. Validation results under 20-MHz BW multisine excitation and injected 80-MHz BW multisine load modulation show improved prediction capabilities with respect to quasi-static or single-input descriptions, allowing for reliable system-level simulations in the presence of DLM.mixedGibiino, Gian Piero*; Lukasik, Konstanty; Barmuta, Pawel; Santarelli, Alberto; Schreurs, Dominique M. M.-P.; Filicori, FabioGibiino, Gian Piero*; Lukasik, Konstanty; Barmuta, Pawel; Santarelli, Alberto; Schreurs, Dominique M. M.-P.; Filicori, Fabi

Uncertainty in Large-Signal Measurements Under Variable Load Conditions

status: publishe