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7.2.1 The Transconductance $ {\mit g}_{\mathrm{m}}$

Fig. 7.9 shows the dependence of the transconductance $ {\mit g}_{\mathrm{m}}$ on $ {\it V}_{\mathrm{GS}}$. For $ {\it V}_{\mathrm{DS}}$, the $ {\mit g}_{\mathrm{m}}$ decrease in compact models is attributed to the change of the effective mean carrier velocity $ {\it v}_{\mathrm{eff}}$. As shown in Chapter 3 the term saturated effective mean carrier velocity is certainly not completely appropriate. Resolving this change in more physical terms the following factors of influence are found.

Figure 7.9: Simulated and measured $ f_T$ and RF-$ g_m$ as a function of $ V_{GS}$ bias.

\includegraphics[width=10 cm]{D:/Userquay/Promotion/HtmlDiss/fig42.eps}

Figure 7.10: $ C_{gs}$ and $ C_{gd}$ as a function of $ V_{DS}$ bias for constant $ V_{GS}$.

\includegraphics[width=10 cm]{D:/Userquay/Promotion/HtmlDiss/fig43.eps}


next up previous
Next: 7.2.2 The Gate Source Up: 7.2 The Bias Dependence Previous: 7.2 The Bias Dependence
Quay
2001-12-21