A metasurface integrated shared aperture antenna for Sub-6 GHz applications

A shared aperture antenna resonating at two sub-6 GHz fRequencies with frequency ratio 1.4 is proposed. A hybrid metasurface constituting two different types of band-stop FSS unit cells resonating at the same frequencies as that of the antenna is placed below it for simultaneous 4 dB gain enhancement of each antenna element at the resonant frequencies. Isolation of more than 35 dB is obtained in both the frequency bands. Equivalent circuit models of the bandstop FSSs have been proposed to explain their physical operation. The two antenna elements have been fed differently for minimising the isolation between them. The first antenna has a CPW feed line. The second antenna has a microstrip feed line. Compared to other existing works, the proposed design is compact and low profile having an aperture size of 50 mm by 52 mm, which makes it suitable for applications of dual sub-6 5 G frequency bands 3-4 GHz and 4.9-5.4 GHz. A prototype of the proposed shared aperture antenna integrated with the hybrid metasurface has been fabricated and measured as a proof of concept. Measured results are in close agreement with the full-wave simulated results.