Dynamic power supply design for high-efficiency wireless transmitters using GaN FETs D. Cucak The topic of this project is application of GaN FETs and filter design methodology in a dynamic power supply for highly efficient wireless transmitters. The main objectives of the filter design are generation of the envelope reference with minimum possible distortion and high efficiency of the amplifier obtained by the optimum trade-off between conduction and switching losses. This optimum point was determined using power losses model for synchronous buck with sinusoidal output voltage. On the other hand, application of GaN FETs showed significant efficiency enhancement comparing to the prototypes with Si MOSFETs with good values for FOM. Project sponsoredby Motivation and Objective Envelope Tracking and Envelope Elimination and Restoration techniques GaNFETs • Wireless and broadband services – growing on a daily basis • Radio base stations – lowefficiency! • The main reason – poor efficiency of linear amplifier • ET and EER – efficiencyincreasementtechniques • EnvelopeAmplifierneedstohave • Fastdynamic response (bandwidth and slewrate) • High efficiency • Proposedtopology: SynchronousBuckwithGaNFETs • GaNdevices – significantlybetterFOM! SynchronousBuckas Envelope Amplifier Efficiencymeasurements Staticcharacteristics: Vin=24V, Rload=4Ω, variable dutycycle Dynamicmeasurements: 64QAM and WCDMA, switchingfrequency: 5MHz Filterdesignmethodology Theoptimumtrade-off betweentheconduction and switchinglosses. Howtominimizethelossesbyfilter design? Design parameter (j2π) = A Vout Modeling of GaNdevices Developedhighfrequencyblack box modelforcommerciallyavailable EPC GaNFETs Switch-basedlargesignal model:losses & performance prediction of ourtopology Modeling of GaNdevices Twomaingoals A physicalmodelthatprovidesa dependence of theswitching behaviour and powerlosseson thetechnologicalparameters of thetransistor CONCLUSIONS Theobtainedefficiencymeasurementsshowedsignificantefficiencyenhancementbyapplication of GaNFETs comparingtostandard Si MOSFETs. For 64QAM and WCDMA signals, EPC1014 prototypeshowedaround 5% higherefficiencycomparingtofastswitching Si BSC016N04LSG, at 5MHz of switchingfrequency. Filterdesignmethodology foroptimumtrade-off betweenthebandwidth and efficiencywasproposed and experimentallyverifiedfor sinusoidal output voltage.