This is likely the easiest one to produce as the frequencies are lower, which is why it was discovered first. TODO original setup.
Also because it is transparent to brick and glass, (though not metal) it becomes good for telecommunication.
Some notable subranges:
Micro means "small wavelength compared to radio waves", not micron-sized.
Microwave production and detection is incredibly important in many modern applications:
Microwave only found applications into the 1940s and 1950s, much later than radio, because good enough sources were harder to develop.
One notable development was the cavity magnetron in 1940, which was the basis for the original radar systems of World War II.
Apparently, DC current comes in, and microwaves come out.
TODO: sample power efficienty of this conversion and output spectrum of this conversion on some cheap device we can buy today.
Video 1. Magnetron, How does it work? by Lesics (2020) Source.
Finance is a cancer of society. But I have to admit it, it's kind of cool. The secret world of microwave networks (2016) Fantastic article.
Video 1. Lasers Transmit Market Data and Trade Execution by Anova Technologies (2014) Source. Their system is insane. It compensates in real time for wind movements of towers. They also have advanced building tracking for things that might cover line of sight.
Video 1. How Microwaves Work by National MagLab (2017) Source. A bit meh. Does not mention the word cavity magnetron!