What is the shortwave band? How are the frequency bands of radio waves divided?

Short wave refers to radio waves with a frequency of 3 30MHz.

Short waves have a short wavelength and are diffracted by ground waves that travel along the earth's surface.

The ability is poor, and the effective distance of propagation is short. Short waves propagate in the ionosphere in the form of sky waves.

The absorption is small, which is conducive to the reflection of the ionosphere. After a single reflection you can get a jump distance of 100 4000km. After several successive reflections from the ionosphere and the earth, the propagation distance is even greater.

This China Radio International Cantonese international broadcast, are not very clear, the same, the rustle of the radio in addition to Mongolian, Korean, Arabic, Vietnamese, Russian French, ** People's Radio Tibetan broadcast, harvest gongs and drums broadcast from 18 o'clock tonight again sounded, 18 o'clock re-launch, 15 o'clock re-launch, China Radio International Cantonese International broadcast Rizhao, 15 o'clock again transmission, short-wave, short-wave frequency again transmission is not very clear.

Low-frequency LF 30-300kHz long hail disturbance wave 10km-1km ground wave mainly transoceanic communication; medium-range communications; communication in underground rock formations; Long-range navigation.

MF MF 1km-100m Ground wave and Sky wave Marine communication; amateur radio communications; mobile communications; Medium-range navigation.

HF 3-30MHz Short Wave 100M-10m Sky Wave and Ground Wave Long-distance Short Wave Communication; International fixed-point communications.

High Frequency VHF 30-300MHz Meter Wave 10M-1m Space Wave Ionospheric Scattering (30-60MHz); meteor aftermath communication; artificial ionospheric communication (30-144MHz); communication with space vehicles; mobile communications;

UHF, UHF, decimeter wave, space-to-space touch-to-inter wave, small-capacity microwave relay communication; （352-420mhz）；tropospheric scattering communication (700-10000MHz); Medium capacity microwave communication (1700-2400MHz).

UHF SHF 3-30GHz Centimeter Wave 10cm-1cm Space Wave Large-capacity microwave relay communication (3600-4200MHz); Large-capacity microwave relay communication (5850-8500MHz); Digital; Satellite communications; Inmarsat communications (1500-1600MHz).

Very High Frequency EHF 30-300GHz mmWave 10mm-1mm Space Wave Communication during re-entry; Waveguide communication.

Content Extensions:

Radio waves refer to electromagnetic waves in the radio frequency band that propagate in free space, including air and vacuum. The shorter the wavelength and higher the frequency of a radio wave, the more information is transmitted in the same amount of time.

Shortwave refers to a wireless radio wave with a frequency of 3 30MHz. The wavelength of short waves is short, and the diffraction ability of ground waves transmitted along the earth's surface is poor, and the effective distance of propagation is short. When short waves propagate in the form of sky waves, they are less absorbed in the ionosphere, which is conducive to the reflection of the ionosphere.

After a single reflection you can get a jump distance of 100 4000km. After several successive reflections from the ionosphere and the earth, the propagation distance is even greater.