In the microwave system, it is often necessary to divide the microwave power into several ways, which is the power distribution problem.
The components that realize this function are called power distribution components, namely coupler, mainly include directional coupler, power distributor and various microwave branch devices. Photoelectric coupler is a kind of electro-optical and electric conversion device which transmits electrical signals with light as medium. It consists of two parts, the luminous source and the light receiver. The luminous source and the optical receiver are assembled in the same airtight shell and separated from each other by a transparent insulator. The pin of the light source is the input end, the pin of the light is the output end, the common luminous source is the light-emitting diode, the light emitting diode, the photosensitive transistor and so on. There are many kinds of photoelectric coupler, such as photodiode type, photoelectric transistor type, photosensitive resistor type, light control thyristor type, photoelectric Darlington type, integrated circuit type, etc. Figure 1 below (the shape has a metal shell package, plastic seal, double row, etc.).