Michel Campovecchio

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This paper presents a characterization method of traps in GaN HEMTs, based on the frequency dispersion of the output-admittance characterized by low-frequency S-parameter measurements. As RF performances of GaN HEMTs are significantly affected by trapping effects, trap characterization is essential for this power technology. The proposed measurement setup(More)
Three power amplifier MMICs at Ka-band frequencies are reported in this paper. The MMICs are realized using AlGaN/GaN HEMTs with a gate length of 100 nm. Two single-stage amplifiers are presented to highlight the potential of this GaN technology. A dual-stage amplifier is designed to reach high power performances. In continuous-wave (CW) operation, MMICs(More)
— This paper describes a fast envelope-tracking circuit capable of 10 MHz (up to 17.5 MHz) bandwidth based on RF GaN switching devices and 50 MHz switching frequency. The efficiency of the VHF converter is 84% to 90% which is comparable to a conventional DC/DC converter for spaceborne application. A demonstrator has been built and mated with a RF GaN HEMT(More)
Two high-efficiency power amplifier MMICs utilizing a 100 nm AlGaN/GaN HEMT MMIC technology at Ka-band frequencies are reported in this paper. They have also been designed in order to ensure high output power and high gain. In continuous-wave (CW) operation, the first three stage power amplifier provides 4.5 W of output power and 33% of(More)
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(More)
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(More)
This paper investigates the impact of irregular pulsed RF signals on the pulse-to-pulse (P2P) stability of a microwave power GaN HEMT amplifier. This study is based on both the time-domain envelope measurements and nonlinear circuit envelope simulations of P2P stabilities. Measurements and simulations are performed with an irregular pulse train that(More)
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(More)