A clover-shaped single-ring element based RA for high efficiency and wideband application in X-band

Abstract

This communication presents an X-band RA using a meandered clover-shaped single-ring element of variable size. A good linear phase range is realized by varying edges of the rectangle. The periodicity of the unit cell is 0.5λo. λo is wavelength in vacuum at 10 GHz. The substrate utilized is Rogers RT/duroid 5880 of dielectric constant r=2.2 with tan = 0.025. Additionally, an air layer of thickness 2mm is used. RA has a circular diameter of 300mm with total elements of 316. A pyramidal X-band horn antenna as standard waveguide WR-90 having an aperture size of 4.5×3.5 cm2 and gain of 13 dBi at operating frequency to excite RA. This RA offers a peak gain of 26dBi and an aperture efficiency of 40% at central frequency. The side lobe level and cross-polarization levels in both planes (E and H) are lower than -15dB and -80dB individually. Besides 3-dB gain bandwidth is 22.2% while 1-dB gain of 12.6 % is obtained. © 2024 IEEE.