Switchable beam diversity antenna

Variable-length parasitic elements provide useful implementation of antenna pattern direction. A switching system is used to change the length of the parasitic elements, which directly affects the role of the elements on the beam direction. Energizing or de-energizing the switching system can rotate the radiation pattern. In other words, the radiation pattern can be directed by increasing or decreasing the length of the parasitic elements. The basic principle is presented with an example of a wire antenna computed using the method of moments. The advantage of the switched parasitic elements concept is that it is a relatively simple system, which can give the adaptive antenna performance of many branch selection or switched diversity.