PI，T濾波器匹配射頻阻抗

　　濾波電路用于從信號中去除不想要的或不想要的成分。當耦合一個以上的信號或頻帶到/從天線，過濾器和匹配的阻抗，如PI濾波器和T濾波器的網絡是在最后的連接從RF收發器到天線的橋梁。這些電路不僅通過一些樂隊而歧視別人，他們也匹配阻抗和允許雙工和循環電路提供全雙工雙向通信。當設計RF部分，很高興知道我們有這些零件在我們的阿森納。

　　本文將討論如何將這些過濾器可以拒絕或傳遞頻段符合特定的標準，以及那些允許多標準傳輸通過相同的路徑。所有的零件，工具，和數據表中提到可以在網站找到的。

　　Limitations of silicon

　　Physical constraints do not allow efficient full-range performance from monolithic silicon. Filters， attenuators， transmission lines， isolation barriers， surge suppression， and more just cannot be done （at least not yet） as effectively in silicon as they can when built up from other substrate materials at larger scales.

　　For example， we can make an on-chip dielectric insulator between sensitive stages on a single-chip die. But， as voltage spikes increase in amplitude， the properties of the silicon insulator just cannot take the higher voltages. Also， unless we insulate in three dimensions， arcing will occur at some point. This applies to surge suppression， too. There is only so much energy a small area can dissipate， absorb， or shunt.