An improved small-signal equivalent circuit of HBT concerning the AC current crowding effect is proposed in this paper. AC current crowding effect is modeled as a parallel RC circuit composed of C _bi and R _bi, with distributed base-collector junction capacitance also taken into account. The intrinsic portion is taken as a whole and extracted directly from the measured S-parameters in the whole frequency range of operation without any special test structures. An HBT device with a 2 20 μm² emitter-area under three different biases were used to demonstrate the extraction and verify the accuracy of the equivalent circuit.

中文翻译：

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包含交流电流拥挤效应的完整小信号 HBT 模型

针对交流电流拥挤效应，提出了一种改进的HBT小信号等效电路。交流电流拥挤效应被建模为由C _bi和R _bi组成的并联 RC 电路，还考虑了分布式基极-集电极结电容。固有部分作为一个整体，直接从整个工作频率范围内的测量S参数中提取，无需任何特殊的测试结构。具有2 20的HBT设备μ米²在三个不同偏压发射极区域被用于证明提取和验证的等效电路的准确性。