Radio frequency DC-DC flyback converter

An RF (radio frequency) dc-dc converter has been developed to demonstrate the possibility of using a flyback configuration at 63 MHz. The converter consists of two sections: a variable pulse width generator (PWG) and a FET switch with a transformer and a detector. The bulk of the design effort was concentrated on improving the efficiency of the switch, the transformer and the detector. Low capacitances of the heterostructure AlGaAs/GaAs FT (HFET), a low leakage inductance of the RF transformer, a fast Schottky diode, multilayer ceramic chip capacitors and surface mount chip resistors made it possible to achieve high efficiencies from 20 MHz to 63 MHz. The "hard switching" 1-Watt converter achieves 60 to 70 percent efficiency, while operating with a wide range of input and output voltages.