Portable Antennas can be everything from a piece of wire hanging from a tree to a base station antenna converted to be used at a remote location. This picture shows a very simple antenna set up for portable operation. Merely unroll it an attach it to some supports and you are ready to communicate. While some may think an antenna like this is too simplistic they may be surprised at its performance if it is mounted correctly.
How 'Portable' Is Portable?
Just look at amateur radio operators for an answer to this. Every year at the end of June the amateur community worldwide participates is what is called "Field Day". This isn't really a day but rather is a complete weekend where everyone gathers around a portable operation to practice their skills. Such skills learned during Field Day encompass setting up portable radio systems, erecting effectie portable antennas, emergency power sources and more. Some of these 'portable' operations are nothing more than a motor home or travel trailer with a crank-up tower mounted on the back with a full sized beam antenna on it. And then there are others that would fit more of the style of a survivalist in that the antennas are portable, the work area is nothing more than a large tent or screened room and the operators more intent on improving their portable skills than they are on scoring a big score for Field Day.
Here are some images of real portable operations with everything from beach front antennas to mountaintop portable operations.
As you can see these folks are running a minimum of radio gear and using effective portable antennas.