A Single-Layer Dual-Band Reflectarray Cell for 5G Communication Systems

Abstract

A single-layer dual-band reflectarray cell is proposed in this work for future 5G systems. A reflectarray unit cell operating at 28/38 GHz is designed by adopting two pairs of miniaturized fractal patches, offering low losses (<0.7 dB) and almost full-phase ranges (≅320°) at both operating frequencies. The proposed configuration allows to achieve very small interelement spacings and negligible mutual coupling effects between the two bands, thus assuring an independent phase-tuning mechanism at both desired frequency bands. The designed compact cell is successfully adopted to demonstrate reflectarrays’ abilities in achieving fixed scanned-beam and/or multibeam patterns, under the dual-band operation mode. Full-wave numerical validations, performed on the synthesized reflectarray structures, confirm the effectiveness of the designed dual-band configuration in achieving independent radiation patterns and quite good bandwidths, at the two designed frequencies. Thanks to its compactness and versatility in achieving both frequency diversity and multibeam/scanned-beam radiation patterns, the proposed unit cell is appealing for future 5G applications.

A Novel Asymmetric Patch Reflectarray Antenna with Ground Ring Slots for 5G Communication Systems

“…The asymmetric patch reflectarray offers a higher gain and wider bandwidth than this dual band design by using just a single patch element in one unit cell. A similar work proposed in [36] also uses the same technique for dual band operation, but with a single polarization. This work also has a narrower bandwidth performance than the asymmetric patch reflectarray antenna.…”

Fractal Metasurfaces and Antennas: An Overview for Advanced Applications in Wireless Communications

“…Moreover, reflectarrays can provide several key skills, such as beam scanning, multi-beam or shaped radiation patterns, polarization diversity, and multi-frequency operations, which are useful for enhancing the capacity, coverage, and throughput performance of telecommunication systems. In order to achieve reflectarray unit cells with multifunctional operation, two fractal based cells have been proposed in [49,50], respectively, for dual-band applications at 28/38 GHz and for dual-band/dual-polarization operation within the Ka band (i.e., 27 and 32 GHz). Thanks to their compact and versatile nature in achieving frequency and/or polarization diversity, both unit cells have been proposed for 5G applications.…”

Dual-Band Dual-Linear Polarization Reflectarray for mmWaves/5G Applications

“…The above frequencies are chosen because they fall into the new 5G cellular bands, which are under consideration at the International Telecommunications Union's (ITU) World Radiocommunication Conference (WRC-19) [31]. Greater frequency ratios (f 2 /f 1 ) can be synthesized through the use of the proposed dual-band fractal cell [24], by properly choosing the fractal dimensions, L fp and S fp . As a matter of the fact, the operating frequency of each pair of patches is inversely proportional to the effective side lengths, L eff fp = (1 + S fp )L fp , so the longer the effective fractal side is, the smaller the resonant frequency will be and vice versa.…”

“…The reflection phase can be separately adjusted, in correspondence of each frequency/polarization, by independently varying a proper defined scaling factor for each element. The same concept has already been adopted by the authors in [24] to design a dual-band (28/38 GHz) reflectarray unit cell. Furthermore, a preliminary investigation of the proposed cell has been illustrated in [25].…”