AMCAD Engineering

Limoges, France

AMCAD Engineering

Limoges, France
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Van Heijningen M.,TNO | De Hek A.P.,TNO | Van Vliet F.E.,TNO | Dellier S.,AMCAD Engineering
EuMIC 2016 - 11th European Microwave Integrated Circuits Conference | Year: 2016

High power amplifier design always requires a compromise between performance and stability. The goal is to design an amplifier that is stable under all operating conditions without sacrificing too much performance by the introduction of stability improvement measures. This paper describes the design of an X-band GaN High Power Amplifier MMIC and the performed stability analysis and measures taken. The amplifier is designed to operate over a wide range of drain bias voltages and input power levels, making the stability analysis particularly important. Using the applied analysis techniques a stable amplifier design has been realized. The measurements show a maximum pulsed output power of 20 W at 30 V drain bias and a maximum PAE of 45% at 18V drain bias. The output power can be adjusted by changing either the drain bias or drive level, while maintaining a good efficiency. © 2016 European Microwave Association.


Dellier S.,AMCAD Engineering | Dehaene T.,Syrlinks | Peragin E.,French National Center for Space Studies
PAWR 2014 - Proceedings: 2014 IEEE Topical Conference on Power Amplifiers for Wireless and Radio Applications | Year: 2014

This paper describes the development of a high-efficiency S-band power amplifier (PA) with power flexibility, based on packaged GaN devices. This amplifier aims to demonstrate the highest power added efficiency (PAE) for a flexible output power from 1 W to 10 W. The approach consists in selecting the suited components of the shelf (COTS), and then in performing comprehensive power characterizations of these devices. The modeling process used enables to design the two stages amplifier with very good predictions of the manufactured PA. The obtained results with an efficiency above 60% for the full range of adjustable RF power between 1 and 10W, are very promising for use in future space applications. © 2014 IEEE.


Rochette S.,Thales Alenia | Vendier O.,Thales Alenia | Langrez D.,Thales Alenia | Cazaux J.-L.,Thales Alenia | And 3 more authors.
European Microwave Week 2012: "Space for Microwaves", EuMW 2012, Conference Proceedings - 7th European Microwave Integrated Circuits Conference, EuMIC 2012 | Year: 2012

This paper deals with the design, manufacture and test of a high efficiency power amplifier for L-band space borne applications. The circuit operates with a single 36 mm gate periphery GaN HEMT power bar die allowing both improved integration and performance as compared with standard HPA design in a similar RF power range. A huge effort dedicated to the device's characterization and modeling has eased the circuit optimization leaning on the multi-harmonics impedances synthesis. Test results demonstrate performance up to 140 W RF output power with an associated 60% PAE for a limited 3.9 dB gain compression under 50 V supply voltage using a single GaN power bar. © 2012 European Microwave Assoc.


Demenitroux W.,Amcad Engineering | Demenitroux W.,French National Center for Scientific Research | Maziere C.,Amcad Engineering | Gasseling T.,Amcad Engineering | And 3 more authors.
European Microwave Week 2010, EuMW2010: Connecting the World, Conference Proceedings - European Microwave Conference, EuMC 2010 | Year: 2010

This paper presents a new macro modeling methodology for solid-state amplifiers (SSAs) or packaged transistors used in communication systems. The model topology is based on the principle of the harmonic superposition recently introduced by the Agilent X-parameters(TM) combined with dynamic Volterra theory. The model results on a Multi-harmonics Bilateral model which handles short-term memory effects. In this work, the behavioral model developed was extracted from time domain load pull measurement performed on one amplifier. Then, the model was used for the simulation of the amplifier's response using a two tones and a CW signal under moderate mismatched load operating conditions. © 2010 EuMA.


Demenitroux W.,AMCAD Engineering | Maziere C.,AMCAD Engineering | Gatard E.,AMCAD Engineering | Dellier S.,AMCAD Engineering | And 2 more authors.
IEEE Transactions on Microwave Theory and Techniques | Year: 2012

This paper presents a complete validation of the new behavioral model called the multiharmonic Volterra (MHV) model for designing wideband and highly efficient power amplifiers with packaged transistors in computer-aided design (CAD) software. The proposed model topology is based on the principle of the harmonic superposition introduced by the Agilent X-parameters, which is combined with the dynamic Volterra theory to give an MHV model that can handle short-term memory effects. The MHV models of 10-and 100-W packaged GaN transistors have been extracted from time-domain load-pull measurements under continuous wave and pulsed modes, respectively. Both MHV models have been implemented into CAD software to design 10-and 85-W power amplifiers in L-and S-bands. Finally, the first power amplifier exhibited mean measured values of 10-W output power and 65% power-added efficiency over 36% bandwidth centered at 2.2 GHz, while the second one exhibited 85-W output power and 65% drain efficiency over 50% bandwidth centered at 1.6 GHz. © 2012 IEEE.


Maziere C.,AMCAD Engineering | Gatard E.,AMCAD Engineering | Enguehard C.,AMCAD Engineering | Xiong A.,AMCAD Engineering | And 2 more authors.
European Microwave Week 2013, EuMW 2013 - Conference Proceedings; EuMC 2013: 43rd European Microwave Conference | Year: 2013

This paper presents a new macro modeling methodology for Solid-State Power Amplifiers (SSPAs) and packaged transistors used in communication systems. The model topology is based on the principle of harmonic superposition recently introduced by Agilent Technologies' X-parameters(TM), upgraded with dynamic Volterra theory. The resulting Multi-Harmonic Bilateral Model takes into account the coupling effects of both short and long-term memories present in non-linear device. In this work, the behavioral model was developed from time-domain load pull measurement results and used to simulate the amplifier's response to a 16-QAM signal with specific regards to EVM and IM3. Another part of this work was to compare the performances predicted by a compact model of a GaN Power Cell made of (15×6×400μm) transistors versus the prediction given by a behavioral MHV model for both continuous and pulsed mode operating conditions. © 2013 European Microwave Association.


Gasseling T.,Amcad Engineering
Microwave Journal | Year: 2012

The main topics involved with model extraction of compact transistor models such as wide band gap (WBG) field effect transistors (FET) such as gallium nitride (GaN) FETs are discussed. It is necessary to determine the transistor's thermal impedance in order to complete an electro-thermal model that can dynamically predict performance as a function of device temperature and self-heating. The thermal circuit provides the equivalent transistor junction temperature as a function of DC power and is used in the various sub-circuit models that are linked to voltages, currents and temperatures. Pulsed IV measurements are used to study the individual trapping effects and differentiate between surface trapping (gate-lag) and buffer trapping (drain-lag). In addition to the parameters obtained from a frequency- domain system, time domain load-pull allows for the measurement of voltage and current waveforms and load lines.


Charbonniaud C.,AMCAD ENGINEERING | Gasseling T.,AMCAD ENGINEERING
2015 IEEE International Conference on Microwaves, Communications, Antennas and Electronic Systems, COMCAS 2015 | Year: 2015

This paper presents a simple methodology to observe the RF waveforms at the drain source current reference plane of the transistor, without using a complete nonlinear model. The aim is to allow Power Amplifier designers starting their work using VNA based harmonic and time domain load pull measurements, and S parameter measurements. The later measurements will be used to extract a linear model first. Then the parameters of the linear model will be used to deembed the load pull measurements directly at the voltage controlled current source plane, in order to enable waveform engineering. Because of the well know theoretic conditions that enable optimum efficiency, this methodology can also be used to avoid time consuming multi-harmonic load pull measurements. Harmonic impedances can be defined accordingly to the knowledge of the operating class addressed, while load pull optimization can be addressed to refine the fundamental matching only. © 2015 IEEE.


Maziere C.,AMCAD Engineering | Gatard E.,AMCAD Engineering | Enguehard C.,AMCAD Engineering | Gustavsen B.,Sintef
International Journal of Microwave and Wireless Technologies | Year: 2013

This paper presents a new macro modeling methodology for solid-state power amplifiers (SSPAs) and packaged transistors used in communication systems. The model topology is based on the principle of harmonic superposition recently introduced by Agilent Technologies' X-parametersTM combined with dynamic Volterra theory. The resulting multi-harmonic bilateral model takes into account the coupling effects of both short- and long-term memory in SSPAs. In this work, the behavioral model was developed from time-domain load pull and used to simulate the amplifier's response to a 16-QAM signal with specific regards to ACPR and IM3. © 2013 Cambridge University Press and the European Microwave Association.


A method for determining optimal source impedance at the input of a device under testing (DUT) in a measurement bench, includes the steps of calibrating a source pull type bench as a measurement bench, adjusting a load impedance and continuous bias of the DUT, generating an electric power signal by the source and injected in the DUT, acquiring input impedances of the DUT and corresponding gain performances.

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