One of the simplest antennas is called a “half-wave dipole,” is a total of ½ wavelength long, and is constructed of two halves, each of which is ¼ wavelength long. This relationship between frequency and wavelength is especially important to antenna design because the wavelength of a frequency is used to calculate many of the dimensions of an antenna’s design. Wavelength (in meters) = 300 / frequency (in MHz)įor example, a frequency of 14.300 MHz has a wavelength of 20.979 meters. In addition to Hertz, which is a unit of frequency, radio waves are sometimes referred to in terms of their length by using the term “wavelength.” As you likely realize, the terms Hertz and wavelength are mathematically related, and the formula below is commonly used to define that relationship. The basic Hertz unit is often preceded with a multiplier such as kilo (1,000) or mega (1,000,000) or giga (1,000,000,000.) Hertz is used in honor of Heinrich Rudolf Hertz, the first person to prove the existence of electromagnetic waves. Radio waves, like all waves in the electromagnetic spectrum, are measured in frequency, and the basic unit of frequency is the Hertz (abbreviated Hz,) which is one cycle per second. Wavelength, Frequency, and Antenna Length Antennas that are not intended to be directional are called “omnidirectional” or “nondirectional,” even though they are never perfectly nondirectional. Antennas are sometimes intentionally created to be antennas (like the antenna on a wireless router) and are sometimes created for another purpose (like the wires on your earbuds,) but also incidentally function as an antenna.Īntennas are always directional-that is, they transmit and/or receive radio waves better in some directions than in other directions. This is the first in a series.Īn antenna is a device that radiates radio waves when supplied with electric power, and/or a device that converts radio waves into electric power. Antennas in GeneralĪlthough the subject of this series of articles is antennas specifically for Wi-Fi use, some background information about antennas in general will be helpful. Better antennas will produce better coverage, and choosing the right antenna is easy if you understand the fundamentals.

Wi-Fi communications depend on radio-frequency energy that is transmitted and received over antennas.

Wifi patch antenna