Why Are Frequency Band Designations So Confusing?

Feb. 19, 2019

A quick google search of “frequency bands” will often provide links to radio spectrum, cellular frequencies, spectrum bands, etc. If the searcher is so bold as to click on Wikipedia’s “Radio Spectrum” page, they will likely encounter tables with swaths of the electromagnetic spectrum designated by the International Telecommunication Union (ITU), IEEE, EU/NATO/US ECM, and waveguide bands. These designations, of course, are all different from the US military, other military, and other country frequency band designations, which are also different from other commonly used designations. When encountering all of these frequency band designations, some of which are more than a little confusing to those who didn’t create the designations in the first place, it is not uncommon to wonder why the nomenclature is so confusing.

A simple answer to the question, is that as radio technology and electromagnetism emerged, there weren’t simple terms available to define the phenomenon being observed and used. Hence the naming of devices and frequencies were often up to the scientist, engineer, or business person that pioneered their use. For example, the application of radio became a designation for the entire radio frequency industry, the engineers that work with radio frequencies, and a frequency band designation loosely constrained between a few hundred kilohertz and a few hundred megahertz. Another example, microwaves, is a little more confusing, as its exact origin is unknown, but could possibly have been used by a news reporter to describe waves that were much smaller than radio waves.

The military radar and military frequency band designations often came about in response to new technologies developed for, or encountered, on the battlefield. For example, L-band between 1 gigahertz and 2 gigahertz was originally used for long range air traffic control and surveillance radar, so the “L” is for “long”. X-band was labeled with the “x”, as it was a secret frequency band used during WWII. K-band is derived from the German word for “short”, “kurz”, and the surrounding bands, Ku-band and Ka-band, stand for “under” and “above”, respectively.

Though the origins of frequency band designations are confusing enough, several organizations, such as the IEEE, ITU, NATO, and etc. have also developed their own standardized approach for spectrum designation. This may sound orderly and a good approach, which it is, but it also has created another side effect. Many application, engineers, and media outlets still used the older designations and common names for frequency bands, so there now is a proliferation of terms to define frequency bands. Depending on the application, many different frequency band designations may be used. For some applications, there is an unspoken agreement to use a particular convention and exclude all others, such as military radar engineers having unwavering dedication to the legacy radar band designations.

For a novice, or someone who hasn’t been introduced to the general confusion of frequency bands, it can be a bit much to become familiar with. This is why frequency charts and tables of the electromagnetic spectrum and frequency bands often decorate an engineer’s desk or lab space.

Voice your opinion!

To join the conversation, and become an exclusive member of Military Aerospace, create an account today!