On the Practical Limitations of Electronic Beamsteering using Metamaterials at 28 GHz
Caldeirinha, R. F. S.
Reis, J. R.
On the Practical Limitations of Electronic Beamsteering using Metamaterials at 28 GHz, Proc IEEE IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications APWC2019, Granada, Spain, Vol. -, pp. - - -, September, 2019.
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This paper will address the practical limitations and constraints of electronic beamsteering using metamaterials at 28 GHz, from design and simulation to physical prototyping. This is sought to lack in the literature for physical prototyping. Electronic beamsteering using active metamaterials is both timely and topical in the context of 5G, particularly when these are applied to single radiating directive sources, such as a horn antenna. In fact, this has been demonstrated by the authors in  at 5.2GHz, using an active square-slot FSS stacked structure loaded with varactor diodes. In the latter, a 5x5 FSS array comprised of 5 stacked layers was considered. The phase of the propagating wave generated by the radiating source has been demonstrated to be fully controlled by applying varying capacitance values to each stacked cell of the structure, and, thus, enabling electronic beamsteering. An extension of the work has been presented in  for higher operating frequencies, aiming at emerging application of 5G and RADAR of the future. In this particular work, beamsteering has been demonstrated by employing discrete surface mount capacitors on a re-shaped FSS unit-cell design to operate in the 28GHz frequency band. Simulation workout proved that 7 FSS layers are necessary to attain the minimum phase delay of 360º, as opposed to the 5 layer design of , to fully control the antenna beamsteering. In fact, a 5x5x7 FSS structure was capable of achieving ±28º of beamsteering at 28GHz.