An accurate charge control approach for modeling excess phase shift in the base region of bipolar transistors

Lumped Models for Assessment and Optimization of Bipolar Device RF Noise Performance

“…Similar to the notation used in [25] and [26], y cb 11b represents the contribution of the base region to the total input commonbase (cb) admittance, y cb 11 . The common-emitter (ce) input and transadmittance follow directly from (9) and (10): y ce 11b = y cb 11b + y cb 21 , y ce 21 = −y cb 21 .…”

A nonquasi-static table-based small-signal model of heterojunction bipolar transistor

“…Equations (10) and (11), shown at the bottom of the page, are derived from (7) and (8), respectively, using (9), , ,…”

“…Some authors have pointed out the fact that high frequency operation of HBT cannot be accurately described by conventional quasi-static (QS) approach [4]- [6]. Recognizing the origin of errors in the QS models at high frequency is the effect of stored minority carrier charge in the neutral base region, several methods have been developed to include this phenomenon into both small and large signal models for HBT [4], [7], [8]. The various approaches of modeling can be grouped into two broad categories.…”

“…The various approaches of modeling can be grouped into two broad categories. The one is a weighting methodology [4], [8], and the other is an infinite series expansion solution which has been implemented by using the effective time constant approach of Seitchik et al [7]. The remaining authors have added transcapacitances on a conventional Gummel-Poon large signal model to make it device-independent [9], [10].…”