Radioaaltoihin

"Radioaaltoihin" is a Finnish term referring to radio waves, the portion of the electromagnetic spectrum used for wireless communication and sensing. Radio waves typically range from about 3 kilohertz to 300 gigahertz (wavelengths from tens of kilometers to a millimeter) and are non-ionizing electromagnetic radiation.

Physically, radio waves are solutions of Maxwell’s equations and can be generated by oscillating electric currents in antennas. They are characterized by frequency, wavelength and polarization, and are commonly modulated in amplitude, frequency or phase to carry information. Propagation modes include line-of-sight, groundwave, and skywave reflections from the ionosphere, each important for different frequency bands and distances.

Applications of radio waves cover broadcasting (AM/FM), mobile telephony, Wi-Fi, satellite communications, radar, navigation (GPS), remote sensing and radio astronomy. Regulation of frequency allocation and transmission power is managed internationally and nationally to prevent interference, with the International Telecommunication Union (ITU) setting many standards.

Health and safety assessments classify typical environmental radio wave exposure as non-ionizing; guidelines and exposure limits are set by organizations such as the World Health Organization and national agencies. Historically, the existence of radio waves was predicted by James Clerk Maxwell and experimentally demonstrated by Heinrich Hertz in the late 19th century, paving the way for modern wireless technologies.