2011 IEEE MTT-S International Microwave Symposium · 2011 · 20 citations · 2 references
EngineeringElectrical EngineeringAnalog ElectronicsMicroelectronicsSemiconductor DevicesDc-dc ConversionDc-dc ConvertersHigh-frequency Power ConversionHigh-frequency Semiconductor DevicesPower AmplifiersRadio-frequency Integrated CircuitsEnvelope TrackingEnvelope Tracking AmplifiersGallium Nitride Power AmplifiersGan-based High-frequency DevicesHigh-frequency Dc-dc ConversionLinearityMeasurementRadio Frequency Power Amplifiers
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 output stage. The C/I measurement for 10-12W RF output power close to saturation show a linearity improvement by 5-8 dB and an efficiency improvement of up to 8 points when compared to the case of no tracking circuit.
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