Radio amateurs are often also nature lovers and therefore often outdoors. When hiking, camping or on holiday, there must be an opportunity for the hobby as well - but with which antenna?
Portable antennas are small antennas that are easy to take with you, because they are usually very light and small packed. They are available for almost all bands - from shortwave to far into the VHF/UHF range. On site they are quickly set up and allow radio operation from the mountain top or holiday location. Of course small antennas are often not as efficient as full-size antennas, but better a small antenna than no antenna at all.
Portable antennas come in many forms, as vertical antennas, small directional antennas or even yagis. Some types require a tuner, others can be tuned exactly to the desired frequency and achieve good SWR without a tuner. Some small models can be attached directly to a radio and do not even need a mounting possibility.
In any case portable antennas make it possible to practice the hobby of amateur radio in almost every situation, even if there is not much space available at home.