Planar Spoof Surface Plasmon Polariton Antenna by Using Transmissive Phase Gradient Metasurface

Abstract

Spoof surface plasmon polariton (SSPP) antennas are of particular importance in communication and radar systems. Currently available SSPP radiation devices are limited to low performance with high side‐lobes because it is extremely challenging to accurately control the wave vector of SSPP and the inherent momentum mismatch between the SSPP and spatial waves. Inspired by the optical principle of reversibility, high‐performance radiation control of SSPP is proposed to be achieved with transmissive phase gradient metasurface (TPGM). The TPGM, placed a meticulously optimized distance above the SSPP propagation structure, can provide an additional opposite wave vector to match the momentum between the SSPP and spatial waves. When the propagating SSPP transmits on the TPGM, it can be decoupled into the free space accurately and flexibly. Numerical results coincide well with the measurements, indicating that the radiation control of SSPP achieves high‐performance and low side‐lobe within 9 to 10.5 GHz with the measured radiation efficiency higher than 50%. The measured maximum efficiency appears at 9.8 GHz for 69%. Thanks to the flexible and accurate manipulation of the dispersion relation of SSPP provided by TPGM, the findings may open an avenue in achieving larger angle scanning antenna.

Spoof surface plasmonics: principle, design, and applications

“…Based on this principle, Cui's group has previously proposed a SSPP emitter by controlling phase modulations produced by the phase-gradient metasurface on the ultrathin metallic strips in 2015 [84], which makes spoof SPP waves convert into spatial propagating waves. Besides, some representative works according to the generalized Snell's law are proposed one after another starting from 2018 [85][86][87][88]. In that year, Chen's group achieved a frequency scanning LWA by decoupling SSPPs via phase gradient metasurface (PGM), as illustrated in figure 12(a) [85].…”

Coplanar Discontinuous Transmission Line Feed for Phase Gradient Metasurface Antenna

“…On the other side, the PGM can be used to radiate directly, that's the PGM antenna, and many feeding techniques have been adopted [16][17][18][19][20][21]. Literature [16] showed a feed of elaborately-designed waveguide to excite the PGM next to it for the in-plane feed antenna design, and the modi ed parallel-plate-like waveguide feed structure was designed in [17], where both feeds are higher than those of PGM cells.…”

“…Literature [16] showed a feed of elaborately-designed waveguide to excite the PGM next to it for the in-plane feed antenna design, and the modi ed parallel-plate-like waveguide feed structure was designed in [17], where both feeds are higher than those of PGM cells. In contrast, the authors put the PGM on the spoof surface plasmon polariton (SSPP) for its radiation, and the rectangular waveguide [18] and the monopole antenna with both metal wall and metallic grooves [19] to excite SSPP were designed, respectively. Additionally, the authors in [20] designed a vertical corrugated metallic strip to excite the parallel symmetrical placed PGM unit cells directly.…”

Optical meta-waveguides for integrated photonics and beyond

“…• Meanwhile, meta-optics are hatching as excellent candidates to construct plasmonic meta-waveguides for controlling surface waves. Abundant research has been invigorated, including efficient multifunctional surface waves excita-tions 70,[112][113][114][115][116][117][118][119][120][121][122] and manipulations [71][72][73][123][124][125][126][127][128] with largely miniaturized device footprint (detailed in Section "Plasmonic meta-devices for controlling surface waves").…”