哪种结构优越? Npn还是Pnp?

Which is the Best Structure? Npn or Pnp?

在分析影响f_(max)的因素后,导出了f_(max)与载流子迁移率的关系式,指出f_(max)不仅与少子迁移率有关,也与多子迁移率相关,是一种综合效应。并推断在材料和器件结构参数相同情况下,Pnp晶体管的f_(max)与Npn晶体管的f_(max)基本相等或稍高。

The relationship between the maximum oscillation frequency fmax and the carrier mobility is deduced on the basis of analysing the factors of effecting on fmax. It is shown that fmax is dependent not only on mimority carrier mobility but al-so on majority carrier mobility,and propotional to the square root of both product. We can infer that fmax of Pnp transistor is equal to or higher than that of Npn transistor.