Reconfigurable Microstrip Magnetic Dipole Antenna With Switchable Conical Beams for Aerial Drone Applications

A novel reconfigurable microstrip magnetic dipole antenna with switchable conical beams is proposed for aerial drone applications. The proposed antenna consists of three sub-cavities that are separated by two groups of shorting posts. To reconfigure the resonant cavities, a number of p-i-n diodes are connected to the shorting posts and are used as RF switches. The antenna is capable of resonating in three different operating states. The theoretical analysis shows that the three resonant modes produce conical beams with different elevation angles. The reconfigurable microstrip magnetic dipole antenna yields an overlapping bandwidth from 2.39 to 2.49 GHz for WLAN 2.4-GHz application and produces switchable conical beams for different operating states. The peak gain is 3.9, 4.0, and 4.3 dBi, respectively, when the elevation angle is 90°, 66°, and 54°. The conical beams have omnidirectional radiation patterns in the azimuth plane for the elevation angles. The proposed antenna shows promise for improving the transmission of aerial drones operating at varying altitudes.