Self-bias for Class B bipolar transistors

Abstract

It is well recognized that the BJT Class B amplifier's conduction angle and gain are dependent on the amplifier's input power level. This dependence is most apparent at lower input signal levels where the transistor is barely turned on. This paper presents an alternative bias network to be used with Class B BJT amplifiers which will compensate for low input power level, resulting in a more constant conduction angle, power gain and input impedance. The results of a simulation experiment which compares the performance of two Class B DC bias circuits for bipolar power transistors as used in a single ended resistive Class B power amplifier are examined.