Influence of Collector Region Design on High-Frequency Large-Signal Performance of SiGe Power HBTs

The impact of collector region design on the high-frequency large-signal power performance of common-emitter (CE) SiGe power HBTs is investigated. Load-pull measurements show that the large-signal power performance of low-breakdown-voltage devices is higher than that of the high-breakdown-voltage device under both class-A and class-AB operation modes. The study indicates that low-breakdown-voltage design is more suitable for CE SiGe HBTs that do not exhibit severe thermal effects to achieve higher power performance provided that sufficient mismatch ruggedness is ensured