Rundstrahlantennen

Rundstrahlantennen, also known as omnidirectional antennas, are radio antennas that radiate or receive radio wave energy essentially uniformly in all horizontal directions. While they transmit equally in the horizontal plane, their radiation pattern typically shows a null or reduced signal strength directly above and below the antenna, often described as a doughnut shape. This characteristic makes them ideal for broadcasting applications where coverage over a wide area is desired without precise aiming.

Common examples of rundstrahlantennen include the simple whip antenna found on many vehicles and portable radios, as well as the vertical dipole and the ground plane antenna. Their construction is generally straightforward, contributing to their widespread use. The effectiveness of a rundstrahlantenne is often measured by its gain, which, for an ideal omnidirectional antenna, is unity relative to an isotropic radiator that transmits equally in all directions. In practice, real-world omnidirectional antennas exhibit slight variations in their radiation pattern due to environmental factors and their physical design. They are crucial components in wireless communication systems like Wi-Fi, cellular networks, and public safety radio.