Patent ID: 6294957
Filing Date: 2001-09-25
Classification: H03F

Abstract:
A RF power amplifier system, comprising:a RF source for providing a train of RF pulses exhibiting RF cycles of a fixed frequency and wherein each pulse is of a fixed amplitude and duration;a DC voltage source;a bridge circuit including a first transistor switch for, when on, connecting said DC voltage source across a load for DC current flow therethrough in a first direction and a second transistor switch for, when on, connecting said DC voltage source across said load for DC current flow therethrough in a second direction;a switch driver for, when enabled, passing said RF pulses for driving said first and second transistor switches on and off at a frequency dependent upon that of said RF pulses and in such a manner that current from said DC voltage source alternately flows in said first and second directions through said load; anda driver controller for providing turn-on signals and selectively applying them to said switch driver for enabling said switch driver for passing said RF pulses to said transistor switches;wherein said driver controller includes logic circuitry responsive to an amplifier turn-on control signal and said RF pulses for enabling said switch driver in such a manner that the first and second transistor switches are turned on and off in synchronism with the start of a said RF cycle and the end of a said RF cycle.