On the reliability of SiGe HBT cascode driver amplifiers

This paper investigates the RF reliability of SiGe HBT cascode driver amplifiers. By subtracting capacitive currents internal to the common-base device from its collector waveform, a more accurate depiction of electrical stress in the I-V plane is achieved, and from this revised load line, RF stress data is better correlated to DC stress data. This novel analysis technique provides a framework for designers to simulate the effects of RF stress using DC data from both TCAD models and measurements, allowing for optimized performance in high power and high frequency applications where reliability concerns often lead to under-utilization of the transistor´s capabilities.