Wideband and Multipolarization Reconfigurable Crossed Bowtie Dipole Antenna

A simple design of a wideband antenna with the capability of switching its operation among five polarization states is proposed. The primary radiator consists of two bowtie dipoles arranged orthogonally through double printed rings. The polarization-reconfigurability is realized by electronically switching three p-i-n-diode pairs. By controlling the current paths from the feeding coaxial line to each dipole arm and among these arms, the antenna can change its radiation among circular polarization (CP) with both rotating senses and linear polarization at three different angles, namely, 0 degrees, 90 degrees, and 45 degrees. The fabricated prototype exhibits an impedance bandwidth (BW) of 37.1% from 2.2 to 3.2 GHz for all polarization states. The axial ratio BW for both CP states is 50.4%, covering the above frequency range. A measured realized gain of greater than 6.6 dBi and a radiation efficiency of around 80% over the overlapped BW are achieved for all states.