E. Chartier

State of the Art 58W, 38% PAE X-Band AlGaN/GaN HEMTs Microstrip MMIC Amplifiers

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 2 2-stages amplifier. To our knowledge, these results present a new state-of-the-art of X-Band MMIC power amplifiers.

43W, 52% PAE X-Band AlGaN/GaN HEMTs MMIC Amplifiers

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.

Fully monolithic Ku and Ka-band GaInP/GaAs HBT wideband VCOs

A family of fully monolithic VCOs utilizing GaInP/GaAs HBTs are presented for the first time. They operate at 14 GHz and 28 GHz with tuning bandwidths ranging from 10.7% to 19.6%. Output powers vary between -9 dBm and +3 dBm with an integrated 6 dB attenuator to reduce pulling. The fabrication yield is higher than 50%. On-wafer measurements show a very small dispersion, and good agreement with the small signal simulations.<<ETX>>

Power GaInP/GaAs HBT MMICs

GaInP/GaAs HBT technology is an excellent alternative to GaAlAs/GaAs HBTs. We present new X-Band power results both on discrete devices and on MMICs obtained using this new type of HBT. 12-2×30-¿m2 finger discrete devices show an output power of 1W at 10 GHz with a power added efficiency of 43% under near class A bias conditions. The dependence of the power gain on the HBT topology has been simulated and that predicts precisely the device performances. First power amplifier MMICs have been produced by Thomson-CSF. Those MMIC amplifiers achieve an output power above 1 W at 10 GHz under both CW and pulsed conditions. The power gain is higher than 12dB at 10 GHz. At the same RF frequency, the power added efficiency reaches 35% and 25% under pulsed conditions (3 ¿s, 10% duty cycle) and CW respectively. These first results are promising, and improved results are expected soon by tuning the output matching network and using higher gain devices.

An Electrothermal Model for GaInP/GaAs Power HBTs with Enhanced Convergence Capabilities

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

Broadband hybrid flip-chip 6-18 GHz AlGaN/GaN HEMT amplifiers

GaN Based HEMTs 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.

Electrical performances of AlInN/GaN HEMTs. A comparison with AlGaN/GaN HEMTs with similar technological process

A study of the electrical performances of AlInN/GaN High Electron Mobility Transistors (HEMTs) on SiC substrates is presented in this paper. Four different wafers with different technological and epitaxial processes were characterized. Thanks to intensive characterizations as pulsed-IV, [S]-parameters, and load-pull measurements from S to Ku bands, it is demonstrated here that AlInN/GaN HEMTs show excellent power performances and constitute a particularly interesting alternative to AlGaN/GaN HEMTs, especially for high-frequency applications beyond the X band. The measured transistors with 250 nm gate lengths from different wafers delivered in continuous wave (cw): 10.8 W/mm with 60% associated power added efficiency (PAE) at 3,5 GHz, 6.6 W/mm with 39% associated PAE at 10.24 GHz, and 4.2 W/mm with 43% associated PAE at 18 GHz.

First demonstration of AlInN/GaN HEMTs amplifiers at K band

AlInN/GaN HEMTs have shown outstanding power performances for high frequency applications, due in particular to their high current densities and their thinner barrier layers than in AlGaN/GaN HEMTs that minimize short channel effects. In this paper, we present the first published power results of two K-band hybrid amplifier demonstrators at 20GHz and 26.5GHz using 0.25µm gate length devices. At these frequencies, respectively, cw RF output power of 4.5 Watts with 20% PAE and 1.65 W with 15.5 % of PAE were obtained. These state-of-the-art results confirm the potential of AlInN/GaN technology for high frequency applications.

Ultra Compact X-Band GaInP/GaAs HBT MMIC amplifiers : 11W, 42% of PAE on 13mm2 and 8.7W, 38% of PAE on 9mm2

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 13mm2. It represents a power density of 0.86W/mm2 of GaAs area. An advanced version on only 9 mm2 of GaAs gives an output power of 8.7W with 38% of PAE. This corresponds to a power density of 0.96W/mm2 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

12W/mm with 0.15µm InAlN/GaN HEMTs on SiC technology for K and Ka-Bands applications

We report on the development of a 0.15μm gate length InAlN/GaN HEMT on SiC substrate technology for applications in K and Ka-Bands. Measurements results of pulsed I-V, S-parameters, load-pull and RF noise figure are presented. Devices exhibit a maximum DC transconductance of 350mS/mm and Idss of 0.95A/mm. Cut-off frequencies FT and Fmag of 45GHz and 100 GHz are reached. Load-pull power measurements at 18GHz allowed us to achieve an output power density of 12W/mm in pulsed mode at Vds=50V. At 30 GHz, 2.5W/mm was measured at Vds=20V. RF noise measurements showed a minimum noise figure of 1.25dB at 20 GHz.