免镇流电阻的非均匀发射极指间距设计对多指功率双极晶体管射频功率性能的改善

RF power performance improvement of multi-finger power bipolar transistor by non-uniform emitter finger spacing design without the use of emitter ballasting resistor

对不添加镇流电阻的非均匀发射极条间距的多发射极条异质结双极晶体管(HBT)的射频功率性能和表面温度分布进行了测量,并与常规采用镇流电阻的多发射极条功率HBT进行了比较。实验结果表明,对具有非均匀发射极条间距的多发射极条HBT,采用US QFI TMS红外测量系统测得的最高表面温度、温度分布均匀性以及采用射频测量系统测得的射频功率增益和功率附加效率,分别低于、好于和高于具有镇流电阻的多发射极条功率HBT的情况。这些结果的取得,得益于采用非均匀发射极条间距改善了多发射极条HBT的热电正反馈和不同发射极条之间的热耦合,以及摆脱了传统HBT加镇流电阻带来的对射频功率性能的负作用。

In this paper,the RF power performance and surface temperature distributions for a multi-finger power hetero-junction bipolar transistor(HBT)with non-uniform emitter finger spacing(NUEFS)without the use of emitter-ballasting-resistor(EBR)are measured,and are compared with a multi-finger power HBT with EBR.The experiment results show that for the multi-finger power HBT with NUEFS,the highest surface temperature is lowered,the uniformity of surface temperature distributions measured by US QFI Infrared TMS is improved,the RF power gain and power-added-efficiency(PAE)are increased compared with the multi-finger power HBT with EBR respectively.These results could be attributed to the improvement in positive thermoelectric feedback and thermal coupling effects among the fingers,and the riddance of adverse impact from emitter-ballasting-resistor used in traditional power HBT.