Multibandvertikaler

A multibandvertikaler, or multiband vertical antenna, is a type of antenna designed to operate efficiently across multiple distinct frequency bands. Unlike a single-band vertical antenna which is typically resonant at a specific frequency, a multiband vertical employs various techniques to achieve resonance and good performance on several amateur radio bands or other radio communication frequencies.

Common methods for creating a multiband vertical include the use of loading coils, traps, or multiple radiating elements of different lengths. Loading coils, placed strategically along the vertical element, electrically lengthen the antenna to achieve resonance on lower frequency bands without requiring an excessively long physical structure. Traps, which are parallel resonant circuits, are incorporated to effectively "short out" sections of the antenna for higher frequency bands, allowing the remaining portion to act as a resonant element. Alternatively, a multiband vertical can consist of several separate vertical elements, each cut for a specific band, mounted on a common base.

The primary advantage of a multiband vertical is its ability to operate on multiple bands with a single antenna feed point, simplifying installation and reducing space requirements compared to deploying multiple single-band antennas. This makes them a popular choice for amateur radio operators with limited space or for portable operations. However, the efficiency and radiation pattern of a multiband vertical can sometimes be compromised compared to dedicated single-band antennas, especially on certain bands, due to the compromises inherent in their design.