(IEEE, 2024) Navarro Cía, Miguel; Beaskoetxea Gartzia, Unai; Teniente Vallinas, Jorge; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Bull’s eye antennas exhibit remarkable directivity
considering their low profile, albeit accompanied by high sidelobes.
This undesirable radiation characteristic is tackled here by reporting a complementary split ring feeding whereby the broadside
space-wave partially responsible for the high sidelobes is cancelled
while the leaky wave is excited effectively. This feeding results in an
asymmetric bull’s eye antenna with minimal profile (∼ 0.73λ0) and
no protrusions on the radiating interface. The fabricated 10-period
antenna operating in the Ka-band shows a directivity of 23.5 dBi, a
sidelobe level of −22.9 dB (>6 dB improvement compared to other
bull’s eye antennas) and a beamwidth of 3.7◦ and 6.7◦ in the E- and
H-plane, respectively.