LF, HF, VHF, and More - The Official Frequency Bands of Radio Communications

Disclaimer

This is my hastily written interpretation/information-regurgitation of the different frequency bands of radio communications. Pretty much all of my information comes from various Wikipedia articles, which I've linked in the appropriate places. Take this post with a grain of salt, thanks!

Introduction

We're all familiar with the Electromagnetic spectrum and where radio frequencies lie on this spectrum - radio waves are the lowest frequency of electromagnetic radiation. 

Above: The Electromagnetic Spectrum (source)

The range of frequencies that radio waves span is vast, so the radio communications community has split the radio spectrum into different classifications. We'll go over each of these classifications below, as well as common uses for waves in each of these bands.

The Bands

SHF - Super High Frequency

Let's start from the shortest radio wavelength band: the Super High Frequency band. This band includes radio waves with frequencies from 3 to 30 Gigahertz. These frequencies actually fall within the microwave portion of the EM spectrum, so SHF waves are actually microwaves, not radio waves. As you may suspect, these are the same waves produced in microwave ovens. However, these waves are also used in communications, such as radar, wireless LANs, satellite communications, satellite phones, and numerous short range terrestrial data links, according to Wikipedia.

UHF - Ultra High Frequency

The second highest frequency band is known as UHF, or Ultra High Frequency. It's defined range is 300 Megahertz to 3 Gigahertz, and it's used for cellphone communications, GPS, Wi-Fi, Bluetooth, satellite phone, and every other damn thing you use every day. Source: Wikipedia

VHF - Very High Frequency

One step lower on the radio spectrum, we encounter the Very High Frequency band, with frequencies of 30 to 300 Megahertz. This band is very actively used for things we all enjoy, such as FM radio and broadcast television (though I'm not sure how many people still watch broadcast TV). This is also the band for amateur radio, marine communications, and air traffic control. Thanks again to Wikipedia for this information.

HF - High Frequency

The next band is called High Frequency, and occupies frequencies of 3 to 30 Megahertz. Communication at this band is often called "shortwave", for reasons I don't understand but you can probably find on Wikipedia. Unlike previous bands, this band allows for long-distance (intercontinental) communications because these waves can bounce off the ionosphere (allowing communications past line-of-sight and past the horizon). This band is used for government broadcasting, weather stations, and amateur communications. You already know that I got all this info from Wikipedia.

MF - Medium Frequency

We're almost at the end! But not yet. The second to last band is called the Medium Frequency band, and contains waves of frequency 300 kilohertz to 3 Megahertz. This band is mostly used for AM radio, navigational radio broadcasting, ship-to-ship communications, as well as transoceanic air traffic control. You can tell that this frequency band is also great for long-distance communication. Here's the MF Wikipedia article.

LF - Low Frequency

At long last, we reach the final frequency band, known as Low Frequency. Waves in this band are 30 to 300 kilohertz, which is equivalant to kilometers in wavelength! This band is also used for some AM broadcasting, as well as government communication, timekeeping, navigation, information, and weather broadcasting. 

Interestingly, these waves are often transmitted close to the ground, as "ground waves", and can travel over hills and beyond the horizon! They experience very low attenuation, and can also interact with some portions of the ionosphere.

VLF - Very Low Frequency

Whoops! I forgot a band. This is the band which is "the ITU designation for radio frequencies in the range of 3–30 kHz, corresponding to wavelengths from 100 to 10 km, respectively" (thanks again Wikipedia).

Conclusion 

Whew! Who even came up with all these internationally recognized categories? Unsurprisingly, it was the United Nations! Specifically, it was the UN's oldest agency - the International Telecommunication Union. This is a very cool organization, which regulates the channels through which we communicate each and every day. I think Wikipedia says it best: "The ITU promotes the shared global use of the radio spectrum, facilitates international cooperation in assigning satellite orbits, assists in developing and coordinating worldwide technical standards, and works to improve telecommunication infrastructure in the developing world." 

Acknowledgements

To Wikipedia and all its authors - thank you! I learn so much when falling down the Wikipedia rabbit hole.

To Rick Ferranti - thanks for getting me interested in radio!