Efficiency of the class B-CE and class B-CC high-voltage wideband amplifiers with a capacitive load

Abstract

The design of high-voltage wideband amplifiers for excitation of ultrasonic actuators and transmitters has problem with limited slew-rate for full range excitation. This problem is connected with value of total power dissipation of transistors, especially for the advantageous class B stage with common emitters. The power dissipation of transistor is substantially dependent on phase shift of capacitive load especially for high frequency range. This paper solves the dependency of the power dissipation and efficiency on phase shift of load and by this way it enables to solve optimum solution of problems connected with this effect. Especially, the maximum slew-rate can be attained by optimum choose of transistors.