Microwave Compact Biconical Antenna with Low Diffraction Lobes for UAV Control Systems with Protection from Jamming

Results of theoretical investigation, numerical simulation, constructive development and experimental measurements of new compact biconical antenna for UAVs are presented in this article. Peculiarity of designed antenna consists in low diffraction lobes in its radiation pattern. This feature was achieved by using dielectric disc in the center region of antenna’s structure between conducting cones. Operating frequencies of antenna in the microwave range ensure protection from electronic jamming systems with quasi-isotropic antennas. Due to high attenuation of radiated electromagnetic waves at microwave frequencies, only directed antennas can create effective jamming of UAV in this band. Such possibility of adverse impact on UAV control system is excluded by low diffraction lobes of applied antenna and a priori unknown operation frequency of wireless control system. Measured results showed that at operating frequency designed antenna with coaxial-to-waveguide transition has VSWR equal to 1.6, maximal value of gain is 6.3 dBi. Measured diffraction lobes of radiation pattern in range of elevation angle −30–+30° from the antenna’s axis are less than −20 dBi. Designed compact biconical antennas were successfully used in new UAV control systems for military applications.