常γ砷化镓电调变容二极管设计与实验研究

电调变容管的C—V特性取决于外延层掺杂浓度分布。为了获得常γC—V特性,外延层掺杂浓度分布应为幂函数。本文假设了一种与实际常γ外延材料掺杂浓度分布比较接近的浓度分布函数,导出了C—V计算公式,并给出器件设计方法。采用平面扩散管芯结构,制得了γ=1和1.25的GaAs电调变容二极管,在2～18GHz宽带线性压控振荡器中获得了满意的使用结果。

Design and Experimental Investigation of GaAs Electronic Tuning Varactor with Constant Gamma

The C-V characteristic of the electronic timing varactor depends on the dis-tribution of epitaxial impurity density. In order to get the constant Gamma C-V characteristic, the epitaxial impurity density should be distributed with a power function. This paper as-sumes a new distribution function of impurity density, which is much identical with the practical one in the epitaxial material. The C-V formula is deduced and the design method of the device is also presented. Using the planar diffusion structure,we have fabricated the GaAs electronic tuning varactors with constant Gamma of 1. 0 and 1. 25,respectively. The results for microwave application are satisf actory in the 2-18 GHz linear wide band VCO using this device.