Dual-mode L-band switched parasitic element antenna for avionics applications

In this paper, a new compact switched beam antenna with directional and omnidirectional modes is proposed. The antenna employs one connector to feed the central element while the switched parasitic elements are located symmetrically around the driven element. By changing the state of the parasitic elements the beam can be steered in 4 possible directions in the azimuth plane. This L-band antenna is designed to operate from 1.03 to 1.09 GHz in the both directional and omnidiretional mode. The return loss of the antenna in the both modes is less than −10 dB. In the directional mode, a front to back ratio of better than 10 dB is achieved over the frequency band of interest in the azimuth plane.