Varactor

变容二极管

A varactor diode uses a p-n junction in reverse bias and has a structure such that the capacitance of the diode varies with the reverse voltage. A voltage controlled capacitance is useful for tuning applications.

变容二极管使用反向偏置的p-n结，并具有这样的结构，使得二极管的电容随反向电压变化。用于调谐应用的电压控制电容是有用的。

The capacitance is controlled by the method of doping in the depletion layer. Typical values are from tens to hundreds of picofarads.

电容由耗尽层中的掺杂方法控制。典型值为十到数百皮法。

Varactor Tuner

变容调谐器

A popular application of the varactor is in electronic tuning circuits, as in television tuners. The DC control voltage varies the capacitance of the varactor, retuning the resonant circuit.

变容二极管的一个常见应用是在电子调谐电路中，例如电视调谐器。直流控制电压会改变变容二极管的电容，从而重新调谐谐振电路。

Schottky Diode

肖特基二极管

Junction of lightly doped n-type semiconductor with a metal electrode.

轻掺杂n型半导体与金属电极的接触。

The junction of a doped semiconductor (usually n-type) with a metal electrode can produce a very fast-switching diode which is mainly used in high frequency circuits or high speed digital circuits. Under forward bias, the electrons move from the n-type material to the metal and give up their energy quickly. There are no holes (minority carriers), so the conduction quickly stops upon change to reverse bias. Schottky diodes find application as rectifiers for high frequency signals.

掺杂半导体（通常为n型）与金属电极的接触可以产生一个非常快速开关的二极管，主要应用于高频电路或高速数字电路。在正向偏置下，电子从n型材料移动到金属并迅速释放能量。由于没有空穴（少数载流子），一旦切换到反向偏置，导电迅速停止。肖特基二极管被用作高频信号的整流器。