Shulou(Shulou.com)11/24 Report--

We, the siege lions engaged in communication, deal with electromagnetic waves every day, often seeing names such as C band, L band, Ku band and Ka band.

Have you ever wondered how these band names came about?

In other words, C band, L band, Ku band, Ka band, etc., all belong to the microwave band we often say. Microwaves are part of the whole electromagnetic wave.

The earliest recorded names for microwave bands date back to World War II.

As we all know, after the Germans occupied the European continent, they wanted to bring Britain to its knees by air blitz. Britain built a large number of radar stations to counter German air strikes.

British radar during World War II is the transliteration of English Radar, which comes from the abbreviation of radio detection and ranging, meaning "radio detection and ranging."

The earliest radar used for search purposes, electromagnetic wave wavelength is 23cm (later changed to 22cm), the British will be defined as the L band. L is the initial letter of "Long" in English. L band, that is, long wave band.

Later, engineers developed radar with a wavelength of 10cm, defined as the S band. S is the initial letter of "short." Yes, S band is short wave, which is "a little shorter" than long wave.

Later, 3cm wavelength radar appeared. This type of radar is specifically used for fire control aiming, so it is called X-band. X, the "crosshairs" from the scope, also stands for a point on the coordinates.

S band and X band radars are widely used on warships. S-band radar is generally used as a warning radar and tracking radar at medium range. X-band radar is generally used as a short-range fire control radar.

During World War II, SG Radar, a radar system on US Iowa class warships, operated in the S band.

In order to combine the characteristics of X-band and S-band radar, researchers have developed a radar with a wavelength of 5cm, which is called C-band. C is the first letter of the word Compromise, meaning "combined."

Seeing that the British radar was so powerful, the Germans began to develop their own radar independently.

They chose 1.5cm as the central wavelength of their radar. This wavelength of electromagnetic waves is called K band (K = Kurtz, German for short).

Unfortunately, the Germans found that K band electromagnetic waves were easily absorbed by water vapor, so they could not be used in rainy and foggy weather.

To avoid this problem, the Germans began to use electromagnetic waves longer or shorter than the K band as radar working waves.

The wavelength slightly longer than K band is called Ku band (Ku, abbreviation for English K-under, meaning below K band). The wavelength slightly shorter than the K band is called Ka band (Ka, which is the abbreviation of English K-above, meaning above K band).

I almost forgot that the earliest radar also used a lot of rice waves, which was called P band (P is the abbreviation of Previous, that is, the prefix of English "past").

Later, these band names derived from radar were further extended to satellite, microwave, radio and television and other communication fields, becoming the usual name of the industry.

Based on these band designations, IEEE (Institute of Electrical and Electronics Engineers) standardized them as follows:

A more complete version of the microwave band specification:

Because this name mixed a variety of systems, very cumbersome and easy to confuse, so, about the North represented by the European and American countries in alphabetical order, redesigned a new naming system to replace it.

The correspondence between the new system and the old system is as follows:

The following picture can be seen more clearly:

Please flip your phone to watch

Nowadays, according to different countries and regions, there are still differences in the way people call bands. Some people like to use old names, while others like new ones. Furthermore, there are differences in the definition of specific numerical ranges.

However, it is believed that over time, these terms and definitions will gradually converge.

Well, that's how electromagnetic waves get their names. Do you understand?

This article comes from Weixin Official Accounts: Fresh Jujube Class (ID: xzclasscom), Author: Xiaozaojun

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.