The frequency-divided channels can be different services or a high performance system that needs parallel data processing to achieve the required processing speed. In a similar way, a system with multiple antennas can be connected to a single front-end. The reasons for the later can be several; high speed data, improved link stability, or a combination of both.
On the one hand, antennas are used to generate electromagnetic waves, on the other hand electromagnetic compatibility (EMC) is all about to control the electronic equipment against unwanted emissions. With a good EMC knowledge, the electronic circuits and systems can be designed to meet the necessary product requirements.