Wideband and High Efficiency 64-Element RDRA Array for Radar Applications

This paper presents the capabilities of an $8\mathrm {\times }8$ Rectangular Dielectric Resonator Antenna (RDRA) planar array with broad bandwidth and high gain. To improve shielding of a multi-stage feeding network, the proposed array is designed using a stripline feeding network with two different substrates. To enhance impedance matching while keeping a sufficient F/B ratio of 20 dB, the lower ground of the stripline has a smaller dimension than the upper ground plane. The proposed array covers the frequency band from 3.79 to 6.29 GHz with 50% fractional bandwidth. The peak realized gain ranges from 18 to 22 dBi, with 85% of radiation efficiency throughout the frequency of interest. The overall size and weight of the array is $215\mathrm {\times } 215 \mathrm {\times }14.5$ mm³ and 650 g, respectively. Furthermore, the radiation patterns appear as low as 15 dB of peak-to-side lobe level with 25 dB cross polarization level, which makes the proposed array suitable for UAS (Unmanned Aerial System) radar applications. The measurements and simulations agree considerably.