HBT characterization and modeling for nonlinear microwave circuit design

Abstract

The objective of this dissertation is to develop accurate and reliable HBT small-signal and large-signal models for the successful design of microwave integrated circuits. Three novel methods for the HBT small-signal modeling are developed. The proposed method, which relies on the strong correlation between extrinsic and intrinsic HBT model elements, can provide physically based model elements, global minimum and fast convergence. For the first time, the Generalized Pencil-of-Function (GPOF) method is applied to characterize the HBT high frequency performance and determine reliable model initial values. The distributed HBT small-signal model is also investigated, which has unique advantages for transistor performance prediction, synthesis and optimization. The improved Gummel-Poon (GP) HBT large-signal model extraction is discussed. Experimental results including the design and fabrication of a SiGe HBT amplifier are also presented. In addition, two improvements on the Vertical Bipolar Inter-Company (VBIC) model are proposed to enhance the performance of the VBIC model and provide a practical approach for the VBIC model development.