Design of an L/S-Band Antenna with Pattern and Polarization Diversity for Aerocraft Application

An L/S-Band antenna for a special aerocraft application is proposed in this paper. This antenna is composed with a microstrip antenna for L-band with circular polarization and unidirectional radiation and a biconical antenna for S-band with vertical polarization and omnidirectional radiation. The microstrip antenna is placed above the biconical antenna and both of their feeding points are at the bottom of the combined antenna, which benefit the integration with circuits behind. The feeding lines for both of the L/S antenna are integrated together and special structures are used to make sure the isolation between the L/S-band signals. Simulated and measured results are given, which show good performances of this antenna.