Emitter-Length Scalable Small Signal and Noise Modeling for InP Heterojunction Bipolar Transistors

In this paper, an emitter-length scalable noise and small signal model for InP heterojunction bipolar transistor (HBT) are presented. A set of scalable expressions for noise parameters based on hybrid-π topology in the low-frequency ranges are derived. The analytical and experimental results show that under the same bias condition, good emitter-length scaling of the noise and small signal model parameters can be achieved between 1.6μm ×10 μm, 1.6μm × 20 μm and 1.6μm × 30 μm InP HBTs.