Large-Signal Performance, Linearity, and Reliability Characteristics of Aggressively-Biased Cascode SiGe HBTs for Power Amplifier Applications

Power performance, linearity, and reliability are investigated for aggressive V
_C
bias (i.e., under strong base-current reversal and pinch-in) on cascode SiGe HBTs, in order to determine the influence of avalanche effects on PA performance and reliability. Moderate gain and linearity degradation are associated with excessive V
_C
bias (pinch-in), and dynamic stress at high V
_C
shows behavior similar to mixed-mode (simultaneous high J
_E
+ high V
_CB
) stress. No significant degradation to PA performance was observed during dynamic stress.