A band-reconfigurable directed dipole antenna

Abstract

A novel reconfigurable directed dipole antenna operated in a wideband or four narrowband modes is presented. The wideband mode (0.83-2.5 GHz) is based on a folded bowtie dipole while the four narrowband modes are based on a length-reconfigurable thin dipole backed by a rectangular cavity. PIN diodes are used as switches at specific locations for choosing different modes. A fully functional prototype is developed and exhibits good performance. The antenna can achieve well-controlled unidirectional radiation patterns and is potentially suitable for cognitive radio.