Reconfigurable Multi-beam On-Chip Patch Antenna Using Plasmonics Parasitic Graphene Strip Array

This paper introduces on-chip patch antenna with electronic beam switching using graphene strip array for wireless communications at 415 GHz. The on-chip patch antenna is printed on silicon/on-chip ground/silicon-oxide multilayer structure for simple integration with system electronic components. Groups of graphene strip arrays are placed parallel to the arms of polygon patch antenna fed by microstrip line connected to its base arm. When the group of N-graphene strips is biased by 15 V, it behaves as conductor strips which act as directors in Yagi-Uda antenna. The radiated beam is directed along with the biased group of graphene strips. When the graphene strips are unbiased 0 V, it behaves as dielectric strips and un-affect the beam direction. An equilateral triangular on-chip patch loaded with two groups of graphene strips is investigated. The effect of a number of graphene strips and their separation gap on the matching bandwidth and beam directivity is studied. It produces impedance bandwidth of 44% with maximum gain of 8.4 dBi and high radiation efficiency of 74%. A single directive beam is electronically switched in directions φ = 45° or φ = 135° by alternate biasing ON the two groups. Dual beams in both directions are achieved when the two groups are biased ON at the same time. A pentagonal-shaped patch loaded with four groups of graphene strips is studied. The single beam is switched in four different directions 0, 45°, 135°, and 180° based on the biased group. Dual, triple, and quad directive beams are radiated from the pentagonal patch with high gain of 7.85 dBi according to the number of biased groups.