Kühn, JuttaJuttaKühnRaay, Friedbert vanFriedbert vanRaayQuay, RüdigerRüdigerQuayKiefer, R.R.KieferMikulla, MichaelMichaelMikullaSeelmann-Eggebert, M.M.Seelmann-EggebertBronner, WolfgangWolfgangBronnerSchlechtweg, M.M.SchlechtwegAmbacher, OliverOliverAmbacherThumm, M.M.Thumm2022-03-042022-03-042010https://publica.fraunhofer.de/handle/publica/22113810.1007/s10762-009-9583-62-s2.0-77949284566The design, realization and characterization of dual-stage X-band high-power and highly-efficient monolithic microwave integrated circuit (MMIC) power amplifiers (PAs) with AlGaN/GaN high electronic mobility transistors (HEMTs) is presented. These high power amplifiers (HPAs) are based on a precise investigation of circuit-relevant HEMT behavior using two different field-plate variants and its effects on PA performance as well as optimization of HPA driver stage size which also has a deep impact on the entire HPA. Two broadband (3 GHz) MMICs with different field-plate variants and two narrowband (1 GHz) PAs with different driver- to final-stage gate-width ratio are realized with a maximum output power of 19-23 W, a maximum power-added efficiency (PAE) of ?40%, and an associated power gain of 17 dB at X-band. Furthermore, two 1 mm test transistors of the same technology with the mentioned field-plate variants and a 1 mm test MMIC support VSWR-ratio tests of 6:1 and 4:1, respectively.enamplifierHEMTgallium compoundpower amplifiermicrostripMMIC667535journal article