Michel Campovecchio

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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 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)
— 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 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 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 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(More)