kvartbølget

Kvartbølget refers to a specific type of antenna construction. The term is derived from the Swedish words "kvart" meaning quarter and "bölget" meaning wave, directly translating to "quarter wave." This type of antenna is designed to have a physical length that is approximately one-quarter of the wavelength of the radio frequency it is intended to transmit or receive. The fundamental principle behind a quarter-wave antenna is its impedance matching. When properly constructed, a quarter-wave antenna, when placed over a ground plane, exhibits an impedance close to 50 ohms, which is a common impedance for radio transmitters and receivers. This impedance match minimizes signal reflections and maximizes power transfer. A common example of a quarter-wave antenna is a simple vertical whip antenna, often seen on vehicles or portable radios. The ground plane can be the vehicle body, the earth, or a dedicated set of radial wires extending from the antenna's base. The effectiveness of a quarter-wave antenna is highly dependent on its precise length and the quality of its ground plane. Deviations from the ideal quarter-wavelength can lead to impedance mismatches and reduced performance.