请教各位大大关于射频信号combine的问题

一般在PCB上，把两路射频信号合并都是用的splitter/combiner，这应该算是常识吧。看了好几本书，都只是说了怎么用，但是没说为什么这么用。
那么问题来了，挖掘机技术。啊不对！问题来了。为什么不能在PCB上把两路射频信号走线直接合并在一起呢?这样有什么潜在的问题和风险么?

一是阻抗加载、二是相位抵减效应！

The most important thing is isolation. Suppose you have 2 Tx, Tx1 and Tx2. If you just merged the trace, it will create the impedance mis-match and phase mis-match. Tx1 power can be also fed to Tx2 and Tx2 power can be also fed to Tx1. In this way, it will create intermodulation distortion at both Tx1 and Tx2. So, we normally use splitter or combiner to combine both Tx power together.

楼上说的好

阻抗匹配、隔离、相位。