如何以及為什么使用PIN二極管的射頻開關(guān)

　　開關(guān)射頻電源在便攜式應(yīng)用中是具有挑戰(zhàn)性的機(jī)電開關(guān)由于尺寸，成本和速度的考慮。雖然PIN二極管提供了一些獨(dú)特的優(yōu)勢相對于其他非機(jī)械的選擇，如CMOS開關(guān)和MEMS結(jié)構(gòu)，他們很難設(shè)計(jì)成一個(gè)電路，除非他們的特點(diǎn)是清楚地理解。

　　本文將介紹射頻開關(guān)的挑戰(zhàn)，并描述PIN二極管操作的基本知識。然后，它將顯示如何設(shè)計(jì)與PIN二極管，然后提供一些現(xiàn)實(shí)世界的PIN二極管的例子，以顯示該技術(shù)是如何推進(jìn)。

　　The RF switching challenge

　　In many applications， it is necessary to switch the RF signal path to route and connect to different antennas， amplifiers， and filters. This need for more switching with higher performance is only growing with the development of MIMO， multiband wireless devices （5G）， and other advanced technologies， especially for portable and battery-powered devices.

　　Since these switches must work into the gigahertz region and higher， nothing about them is simple： their design， their underlying technology， the layout on the PC board， or matching their performance to the application priorities.

　　Each of these technologies offers tradeoffs in key performance parameters such as bandwidth， insertion loss， isolation， switching speed， and power handling （Figure 1）。

　　（Note： “hybrid” switches combine PIN diodes and FET-based components.）