Frequency and Polarization Reconfigurable Antenna for Airborne Application

Reducing weight and improving stealth capacity of onboard airborne system is always been a desirable feature. Reduction in number of antennas mounted onboard for communicating with ground system improves both the values of the system. This paper proposes a new design to replace the presently used three antennas working at different frequencies (two at S band, one at C band) and polarization by a frequency and polarization reconfigurable antenna. The microstrip patch antenna is designed and optimized in such a way that interconnection between patches tuned antenna from higher to lower frequency. Three coaxial feed points are provided for three operational frequencies. Polarization reconfigurability from circular polarization (CP) to linear polarization (LP) is achieved through positioning of these feed points and interconnection via switching. Switches ON state have been modeled with microstrip line connection. The Comparison of simulation and measurement result is presented. The measured results are in good agreement with simulation results. The measured return loss is better than 12 dB at three resonant frequencies and axial ratio is 3 dB, which meets the operational requirements.