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ABSTRACT: This paper reports a package synthesis method in order to ensure good performances in PAE, output power and bandwidth. The internal matching circuits of the optimized package enable to reach the best impedance pre-matching at fundamental frequencies impedances seen by and also to confine the harmonic the internal GaN power bar into safe-efficiency regions whatever the external impedances presented to frequencies. Thus, the designed package ensures that the the second harmonic impedances seen by the internal active die package at second harmonic frequencies. In a 500 environment, the packaged GaN HEMT delivers 55 W output power associated with 60% PAE and 13.3 dB power gain at 2.7 GHz. By optimizing source and load impedances at the fundamental frequencies, the packaged GaN HEMT demonstrates more than 58% PAE from 2.6 GHz to 3.0 GHz.
Integrated Nonlinear Microwave and Millimetre-wave Circuits (INMMIC); 01/2012
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ABSTRACT: The electrical modeling of power packages is a major issue for designers of high-efficiency hybrid power amplifiers. This paper reports the synthesis and the modeling of a packaged Gallium nitride (GaN) High electron mobility transistor (HEMT) associ- ating a nonlinear model of the GaN HEMT die with an equivalent circuit model of the package. The extraction procedure is based on multi-bias S-parameter measurements of both packaged and unpackaged (on-wafer) configurations. Two different designs of 20 W packaged GaN HEMTs illustrate the modeling approach that is validated by time-domain load-pull measure- ments in S-band. The advantage of the electrical modeling dedicated to packaged GaN HEMTs is to enable a die-package co-design for power matching. Internal matching elements such as Metal oxide semiconductor (MOS) capacitors, Monolithic microwave integrated circuits (MMICs), and bond wires can be separately modeled to ensure an efficient optim- ization of the package for high power Radio frequency (RF) applications.
International Journal of Microwave and Wireless Technologies 01/2012; 4(5):495-503.
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ABSTRACT: Reported is a design methodology to efficiently control source and load impedances of a power GaN HEMT at the second-harmonic frequency inside a metal ceramic package. Second-harmonic source control is more precisely investigated. A specific filter is implemented at the gate side within the package to transform external source impedances into negative reactances seen by the internal device at second-harmonic frequencies. Whatever the external source termination presented at second-harmonic frequencies, source impedances seen by the internal die are confined to high efficiency regions. This methodology is applied to a 20 W packaged GaN HEMT using internal control of input and output second-harmonic impedances to reach more than 70% of power-added-efficiency (PAE) on 30% relative bandwidth in S-band.
Electronics Letters. 01/2012; 48(13):770-772.
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ABSTRACT: Ce papier expose une nouvelle méthodologie d’optimisation d’un bo^itier de transistor GaN pour la conception d’amplificateur très haut rendement et large bande, fournissant 70% de PAE sur 1GHz en bande S. Ces performances sont obtenues en optimisant uniquement les impédances à la fréquence fondamentale. En effet, le contrôle des impédances aux fréquences harmoniques du transistor est réalisé lors du câblage de la puce dans son bo^itier. Des mesures load-pull à 3.2GHz ont démontré que la PAE atteint 72% en optimisant uniquement le fondamental, soit 8 points de PAE en plus par rapport à un transistor sous pointes. De plus, les variations de la PAE à l’harmonique 2 sont de 6 points seulement ce qui assure un fonctionnement haut rendement du transistor en bo^itier.
Journées Nationales Micro-ondes (JNM); 01/2011
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ABSTRACT: This paper proposes a packaged transistor modeling using lumped elements. This model allows studying the input impedance dispersion when a range of variation is applied to various package components. This dispersion is also highlighted when a load impedance variation is applied to the package transistor. It is demonstrated that this dispersion can be corrected using a specific input pre-matching and by having a very good information about input return loss contours. Moreover, this specific packaged transistor presents input impedance close to 50$Ømega$ over [3.0-3.8]GHz.
Integrated Nonlinear Microwave and Millimeter-Wave Circuits (InMMIC); 01/2011
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ABSTRACT: This paper presents a method for synthesizing the package of power GaN transistors in order to achieve wideband matching at harmonics. The proposed method is applied to optimize the package of a 15W power GaN HEMT for high efficiency performance over 39% bandwidth (S-band). It is demonstrated that the internal pre-matching of package ensures that the impedance seen by the GaN die at the second-harmonic frequency remains confined inside a high-efficiency region over a wide bandwidth whatever loads presented to the output of the package. In fact, when the 2nd-harmonic frequency termination of the package is varied all over the entire Smith Chart, the packaged transistor demonstrates a limited variation of PAE (70±3)% at 3.2GHz. Thereby, this method allows the designer to synthesize the external output matching of the packaged transistor only at the fundamental frequencies without imposing constraints on the 2nd harmonic loads.
European Microwave Conference (EuMC); 01/2011
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J. Chéron,
M. Campovecchio,
D. Barataud,
M. Stanislawiak,
C. Tolant,
P. Eudeline, D. Floriot,
S. Heckmann,
L. Favède,
F. Temcamani,
C. Duperrier
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ABSTRACT: This paper reports the design and measurement of a GaN power amplifier whose output loads are optimised at fundamental and 2<sup>nd</sup> harmonic over a wide bandwidth (20%) in S-Band to reach maximum power added efficiency (PAE). The design methodology is described in the paper. Two power amplifiers have been built. The first one is optimized at fundamental and 2<sup>nd</sup> harmonic while the other one is only optimised at fundamental. Comparisons of power measurement results demonstrate the interest of optimising load impedances at the 2<sup>nd</sup> harmonic over large bandwidths for GaN HEMTs. When loaded by the matching circuit optimised at the 2<sup>nd</sup> harmonic, the packaged GaN exhibits 23.4Watts (9.7W/mm) output power associated to 15.2dB power gain and 69% PAE at the low frequency of the bandwidth (f<sub>min</sub>). The paper also proposes a new matching architecture at 2<sup>nd</sup> harmonic frequency.
Microwave Integrated Circuits Conference (EuMIC), 2010 European; 10/2010
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S. Piotrowicz,
Z. Ouarch,
E. Chartier,
R. Aubry,
G. Callet, D. Floriot,
J.C. Jacquet,
O. Jardel,
E. Morvan,
T. Reveyrand,
N. Sarazin,
S.L. Delage
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ABSTRACT: This paper presents the results obtained on X-Band GaN MMICs developed in the frame of the Korrigan project launched by the European Defense Agency. GaN has already demonstrated excellent output power levels, nevertheless demonstration of excellent PAE associated to very high power in MMIC technology is still challenging. In this work, we present State-of-the-Art results on AlGaN/GaN MMIC amplifiers. An output power of 43W with 52% of PAE was achieved at 10.5 GHz showing that high power associated with high PAE can be obtained at X-band using MMIC GaN technology.
Microwave Symposium Digest (MTT), 2010 IEEE MTT-S International; 06/2010
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ABSTRACT: GaN technology has gained a lot of attention in Europe over the last few years for various domains including RF electronics. This paper will try to summarize the current status achieved and illustrate it with a few representative examples. Due to the importance of the subject this paper will focus solely on the RF electronics related topics, which should be of major interest in the frame of this conference. Aspects covering material, devices up to circuits and module integration will be addressed.
Compound Semiconductor Integrated Circuit Symposium, 2009. CISC 2009. Annual IEEE; 11/2009
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S. Piotrowicz,
E. Morvan,
R. Aubry,
S. Bansropun,
T. Bouvet,
E. Chartier,
T. Dean,
O. Drisse,
C. Dua, D. Floriot, [......],
D. Lancereau,
J.O. McLean,
G. Lecoustre,
A. Martin,
Z. Ouarch,
T. Reveyrand,
M. Richard,
N. Sarazin,
D. Thenot,
S.L. Delage
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ABSTRACT: This paper presents the results obtained on X-Band GaN MMICs developed in the frame of the Kerrigan project launched by the European Defense Agency. A new step was achieved, 58 W of output power with 38% PAE in X-Band were obtained using an 18 mm <sup>2</sup> 2-stages amplifier. To our knowledge, these results present a new state-of-the-art of X-Band MMIC power amplifiers.
Compound Semiconductor Integrated Circuits Symposium, 2008. CSIC '08. IEEE; 11/2008
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S. Piotrowicz,
R. Aubry,
E. Chartier,
O. Jardel,
J.C. Jacquet,
E. Morvan,
B. Grimbert,
G. Lecoustre,
S.L. Delage,
J. Obregon, D. Floriot
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ABSTRACT: GaN Based HEMT's have shown superior power-frequency performances than lower band-gap materials. In this paper, we present the design of broadband hybrid 6-18 GHz amplifiers based on AlGaN/GaN HEMT technology with a flip chip approach. Measurements of a single ended amplifier based on a 0.6mm gate width device allow us to achieve more than 1.8W in the [6.5-16] GHz bandwidth corresponding to a power density of 3W/mm. A Maximum output power is obtained at 8 GHz at 2.7W corresponding to 4.5W/mm. Average typical PAE values higher than 17% in the bandwidth with a maximum of 39% were obtained. A balanced amplifier based on two single ended amplifiers was also realized. The output power is above 2.8W in the [7-17] GHz bandwidth corresponding to a power density of 2.4W/mm. Maximum output power is obtained at 7.5 GHz at 4.5W corresponding to 3.8W/mm.
Microwave Symposium Digest, 2008 IEEE MTT-S International; 07/2008
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ABSTRACT: A report is presented on the specific design of a GaN HEMT cascode cell demonstrating significant improvement for flip-chip distributed power amplifiers. The active device is a 8 times 50 mum AlGaN/GaN HEMT grown on SiC substrate. The GaN-based wafer integrating the active part is flip-chipped onto an A1N substrate via electrical and mechanical bumps. The cascode cell integrates matching elements for power optimisation of wideband distributed amplifiers up to their maximum frequency and for intrinsic power balance of the cascode cell. Additional resistors are integrated to ensure bias path and stability, this last one being decisive for the studied application.
Electronics Letters 02/2008; · 0.96 Impact Factor
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ABSTRACT: 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.
IEEE Transactions on Microwave Theory and Techniques 01/2008; · 1.85 Impact Factor
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ABSTRACT: This paper reports on the design of a cascode GaN HEMT cell dedicated to 4-18 GHz flip-chip distributed power amplifier. The active device is a 8x50 mum AlGaN/GaN HEMT grown on SiC substrate. The GaN-based die which integrates the active cascode cell and its matching elements is flip-chipped via electrical bumps onto an AIN substrate. The matching elements of the balanced cascode cell are composed of series capacitances on the gate of both transistors with additional resistances to insure stability and bias path. The series capacitor on the gate of the 1st transistor is added for the distributed amplifier optimisation while the series capacitor on the gate of the 2 <sup>nd</sup> transistor is dedicated
Microwave Integrated Circuit Conference, 2007. EuMIC 2007. European; 11/2007
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ABSTRACT: A circuit modeling drain-lag effects has been added in a non-linear electrothermal model for AlGaN/GaN HEMTs. Modeling these trapping effects allows a better description of the I-V characteristics of measured devices as well as their large-signal characteristics. This drain-lag model is well suited to preserve the convergence capabilities and the simulation times of the non linear models of these devices. This paper presents our drain-lag modeling approach, the implementation of the model in CAD software, its operating mode, and also the parameters extraction from measurements. Then, significant comparison results will be reported on pulsed IV and large signal measurements with an AlGaN/GaN HEMT transistor.
Microwave Symposium, 2007. IEEE/MTT-S International; 07/2007
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Journées Nationales Micro-ondes (JNM); 01/2007
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ABSTRACT: A new model for GaInP/GaAs power heterojunction bipolar transistors (HBT) is proposed. This non-linear electrothermal and fully scalable model was designed with closed-form equations in order to reduce simulation times in complex circuits like high power amplifiers (HPA) and to have good convergence capabilities at high compression levels. This paper presents model topology and shows parameters extraction from pulsed I-V, pulsed [S]-parameters measurements. Simulations performed on a two-stage HPA with 20 HBTs devices have demonstrated the good convergence properties as well as a good correlation with measurements
European Microwave Integrated Circuits Conference, 2006. The 1st; 10/2006
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ABSTRACT: HBT power technology offers an excellent compromise for high power and high efficiency amplifiers up to the Ku band. In order to reduce cost and size of THALES T/R modules, we developed compact high power MMIC amplifiers with innovative transistor designs in X-band. In this paper, we present the performances of two GaInP/GaAs MMIC power amplifiers. The first one delivers an output power of 11.2W with 42.3% of PAE with a chip size of 13mm<sup>2</sup>. It represents a power density of 0.86W/mm<sup>2</sup> of GaAs area. An advanced version on only 9 mm<sup>2</sup> of GaAs gives an output power of 8.7W with 38% of PAE. This corresponds to a power density of 0.96W/mm<sup>2</sup> of GaAs. To our knowledge, this is the state of the art performances in terms of power density per GaAs surface for MMIC power amplifiers above 8W. These power MMIC circuits constitute very attractive chips for phased array antennas, airborne radar, telecommunications or satellite links
Microwave Symposium Digest, 2006. IEEE MTT-S International; 07/2006
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ABSTRACT: This paper reports on the design of a cascode GaN HEMT distributed power amplifier demonstrating significant improvement of the best power performances reported to date. The active device is 8 × 50 μm AlGaN/GaN HEMT grown on siSiC. The distributed power amplifier integrates 4 cascode cells capacitively coupled to the gate line for power optimization. The active part made of the 4 cascode cells is implanted on a GaN-based wafer while the distributed passive part made of the interconnection lines is implanted on an AlN substrate. Finally, the GaN-based wafer integrating the active part is flip-chipped onto the AlN substrate via electrical and mechanical bumps. The flip-chip integrated circuit demonstrates a mean gain of 10dB and input/output matching lower than -10dB over the 4-18GHz bandwidth. At an input power of 29dBm (1 dB comp.), power simulations exhibit a mean output power of 37.6dBm with a standard deviation of 0.3dB, a power gain of 8.6dB and 16% of PAE over the band. At an input power of 31dBm (2dB comp.), the distributed amplifier achieves a mean output power of 38.6dBm, a power gain of 7.6dB and 18% of PAE.
Microwave Conference, 2005 European; 11/2005
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ABSTRACT: This paper reports on the design of a cascode GaN HEMT distributed power amplifier demonstrating significant improvement of the best power performances reported to date. The active device is a 8/spl times/50 /spl mu/m AlGaN/GaN HEMT grown on siSiC. The distributed power amplifier integrates 4 cascode cells capacitively coupled to the gate line for power optimization. The active part made of the 4 cascode cells is implanted on a GaN-based wafer while the distributed passive part made of the interconnection lines is implanted on an AlN substrate. Finally, the GaN-based wafer integrating the active part is flip-chipped onto the AlN substrate via electrical and mechanical bumps. The flip-chip integrated circuit demonstrates a mean gain of 10 dB and input/output matching lower than -10 dB over the 4-18 GHz bandwidth. At an input power of 29 dBm (1 db comp.), power simulations exhibit a mean output power of 37.6 dBm with a standard deviation of 0.3 dB, a power gain of 8.6 dB and 16% of PAE over the band. At an input power of 31 dBm (2 dB comp.), the distributed amplifier achieves a mean output power of 38.6 dBm, a power gain of 7.6 dB and 18% of PAE.
Gallium Arsenide and Other Semiconductor Application Symposium, 2005. EGAAS 2005. European; 11/2005
