A fast and smooth data transmission is critical in today’s world. Network and server systems are designed to process and forward information at lightning fast speeds. To achieve this, many of these applications depend on frequencies in the three-digit megahertz (MHz) range.

在当今世界，快速、流畅的数据传输至关重要。网络和服务器系统旨在以闪电般的速度处理和转发信息。为了实现这一目标，其中许多应用都依赖于兆赫（MHz） 范围内的频率。

Such high frequencies cannot be generated with an AT-crystal in the fundamental tone. Although quartz discs with a fundamental frequency of 40 to 50MHz are feasible, their production involves considerable effort and corresponding costs. For this reason, “overtone crystals” are usually used for frequencies above 20 megahertz.

基频的AT晶体无法产生如此高的频率。虽然基频为40至50MHz的石英晶片是可行的，但其生产需要相当大的努力和相应的成本。因此，“泛音晶体”通常用于20兆赫兹以上的频率。

Overtone vs. Fundamental Tone 泛音与基频

Every quartz blank has its basic frequency. Besides this “fundamental tone”, each quartz disc has several overtones. When electric voltage is applied to the quartz, it oscillates on its fundamental tone. Its overtones are also triggered in this process, but their signal is significantly weaker than that of the fundamental tone. In fact, most of the time the overtone signal results in nothing more than normal phase noise.

每个石英晶体毛坯都有其基本频率。除了这个“基频”之外，每个石英晶片还有几个泛音。当电压施加到石英晶体上时，它会根据其基频振荡。它的泛音也在此过程中被触发，但它们的信号明显弱于基频信号。事实上，大多数时候泛音信号只会产生正常的相位噪声。

By clever construction of the oscillator circuit, it is possible to actuate the overtone of the quartz instead of the fundamental tone. Therefore, an additional resonant circuit is added to the oscillator circuit in order to amplify the overtone signal of the quartz.

通过巧妙地构建振荡器电路，可以驱动石英晶体的泛音而不是基频。因此，在振荡器电路中添加了一个额外的谐振电路，以放大石英晶体的泛音信号。

This technique allows engineers to “squeeze” frequencies far above its fundamental tone out of a quartz crystal. For example, if a quartz oscillates in the fundamental tone at 20MHz, the third overtone oscillates at 60MHz and the fifth overtone oscillates at 100MHz. Due to the electronic properties of the oscillator circuit, the overtones can only be stimulated in the odd integer range.

这种技术允许工程师从石英晶体中“抑制”远高于其基频的频率。例如，如果石英晶体在20MHz的基频中振荡，则第三个泛音在 60MHz 处振荡，第五个泛音在100MHz处振荡。由于振荡器电路的电子特性，泛音只能在奇整数范围内受到激发。

How Does an Overtone Quartz Oscillate? 泛音石英晶体如何振荡？

The remaining question is about the shape of an overtone quartz’s oscillation. You can imagine the overtone oscillation as a multiple of the crystal’s fundamental oscillation.

剩下的问题是关于泛音石英晶体振荡的形状。您可以将泛音振荡想象为晶体基频振荡的倍数。

Oscillation of a Thickness Shear Oscillator in its Fundamental Tone

Let’s take the thickness shear oscillator as an example: Put under voltage, top and bottom of the quartz move in opposite directions in the fundamental tone. However, in the overtone, not only the upper and lower sides of the quartz oscillate, but also the molecular layers inside it. These layers also move in opposite directions, just like the crystal’s top and bottom in the fundamental tone. The quartz does not only vibrate on its outside, but “in itself”, so to speak.

以通过厚度切割晶体振荡器为例：在电压作用下下，石英晶体的顶部和底部在基频方向相反。然而，在泛音中，不仅石英晶体的上下两侧振荡，而且内部的分子层也会振荡。这些层也朝相反的方向移动，就像石英晶体的顶部和底部在基频中一样。石英晶体不仅在外部振动，而且可以这么说“本身”也在振动。

Figuratively speaking, one can visualize an overtone quartz like a pendulum attached to a long chain. In the fundamental tone, only the pendulum swings, but in the overtone each individual chain link swings as well.

形象地说，人们可以想象泛音石英就像一个连接到长链上的钟摆。在基频中，只有钟摆摆动，但在泛音中，每个单独的链节也会摆动。

Frequencies of up to 200 Megahertz  频率高达200兆赫兹

A quartz driven by its overtone can generate a frequency of up to 200MHz, thus creating the perfect base for fast data transmission in communication technology.

由其泛音驱动的石英晶体可以产生高达200MHz的频率，从而为通信技术中的快速数据传输奠定了完美的基础。