In this paper, an assessment up to 220 GHz of industrial organic laminate substrate technology to integrate millimeter-wave (mmW) waveguide to suspended stripline (SSL) transition is proposed. A WR5 waveguide transition has been manufactured and insertion loss (IL) of 1.4 dB @ 140 GHz and 4.2 dB @ 220 GHz has been achieved, competing with standard approach using a quartz substrate solution with III-V technology. This promising performance paves the way of cost effective mmW and sub-THz module manufacturing leveraging high volume manufacturing packaging processes developed for Si based technologies.

The properties of a new class of electromechanical resonators based on GaN are presented. By using the two-dimensional electron gas (2-DEG) present at the AlGaN/GaN interface and the piezoelectric properties of this heterostructure, we use the R-HEMT (Resonant High Electron Mobility Transistor) as an active piezoelectric transducer up to 5MHz [1]. In addition to the amplification effect of piezoelectric detection, we show that the active piezoelectric transduction has a strong dependence with the channel mobility that is controlled by a top gate. This allows to envision highly tunable sensors with co-integrated HEMT electronics.

We report on the development of a multi-finger InP/GaAsSb DHBT technology, optimized for the fabrication of RF MMICs. Geometry (number of fingers) and structure optimization has allowed to get F T ~200 GHz and F MAX >300 GHz, to suit microwave applications. Special attention has been paid to critical thermal behavior. Key devices have been modeled using a modified Gummel-Poon model. Based on these models, and a passive devices library, RF amplifiers have been designed to operate at 60 GHz, fabricated using the developed process, using 2-finger devices, and measured. 1-stage amplifier delivers 5.5 dB, and 2-device 2-stage amplifier achieves up to 10 dB gain.

CNFETs have been characterized under large signal conditions at 600 MHz with an original active load pull setup using a LSNA. A non linear model of CNFET has been established and validated by comparison with the experimental results. Using this non linear model, design of circuits can be considered, allowing the optimization in non linear behavior.

Over the last years, there is an increasing need to know and characterize the non linear behaviour of most high frequency semiconductor devices. For that, a new and original automatic active load-pull system based on a large signal network analyzer is presented which allows to carry out an accurate non linear characterization with very high load reflection coefficient (more than 0.96) under microwaves probes. After describing the setup and the calibration procedure, a dedicated study has been performed in order to validate the active load-pull system and to know and evaluate the good accuracy of non linear measurements. At non linear model of AlGaN/GaN HEMT device has been established in order to compare measurements and simulations.

Overthelast years, there isanincreasing needto knowandcharacterize thenonlinear behaviour ofmosthigh frequency semiconductor devices. Forthat, a newandoriginal automatic active Load-Pull system based onaLarge Signal network Analyzer ispresented whichallows tocarry outanaccurate non linear characterization withveryhighloadreflection coefficient (morethan0.96) undermicrowaves probes. After describing the setup andthecalibration procedure, adedicated study hasbeen performed inorder tovalidate theactive load-pull system andto knowandevaluate thegoodaccuracy ofnonlinear measurements. Atnonlinear modelofAlGaN/GaNHEMT device hasbeen established inorder tocompare measurements andsimulations.

DC‐ and RF‐pulsed measurements of AlGaN/GaN HEMTs on high resistive silicon (111) substrate are achieved under probes in the 300–525 K temperature range. Current collapse and heating effects are studied and it demonstrates the high temperature properties of these devices. Hence the potential of this technology for power applications at microwave frequencies is confirmed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2301–2305, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21897

AlGaN/GaN HEMTs are realized on a sapphire substrate without a field plate, for power applications at microwave-frequencies using a new Ar+ ions implant-isolation technology. The first results obtained are veri v good in terms of device isolation. (c) 2005 Wiley Periodicals, Inc.

In this letter, we present the process and power microwave measurements of 0.07-mu m Al0.25Ga0.75As/In-0.22 Ga0.78As pseudomorphic high-electron mobility transistors (PHEMTs). These devices are passivated and exhibit a Ft of 125 GHz, a current density of 750 mA/mm associated to a high breakdown voltage of 4 V at open channel. Careful power measurements performed at 94 GHz have allowed to demonstrate for the first time an output power of 876 mW/mm associated with 5.7-dB power gain and a power added efficiency of 29% on a PHEMT on GaAs substrate.

The benefit of high drain-source bias voltages of GaN devices on sapphire substrates for high linearity applications is demonstrated. Whatever the output power densities considered, the corresponding intermodulation ratio is at least 20 dB better than usual PHEMT devices on GaAs substrates for the same power density. This study demonstrates that GaN devices are ideal candidates for applications requiring high power and high linearity behaviours simultaneously.

The advantage of planar technology for the AlGaN/GaN HEMTs realization is demonstrated in this paper. A breakdown voltage closed to 100 V and an output power density of 4 W/mm at 4 GHz have been measured on a 2x25x1.5 μm2 HEMT on sapphire substrate. These results are very promising because the devices have not been passivated, and no T gate has been achieved. Moreover, planar technology offers the advantage of a better reliability. At present time, it is the best power result obtained with an isolation by argon implantation.