Sub-wavelength array of planar antennas with defect oval rings based on far-field time reversal

Abstract

A compact planar sub-wavelength array is proposed, which has planar antenna elements etched with defect oval rings on the surface. The array demonstrates a property of 1/20 wavelength super-resolution combined with time-reversed electromagnetic waves. This design is simple in structure, easy to integrate and convenient for the printing design of circuit boards.Introduction: Time-reversed electromagnetic waves combined with some special microstructures can perform the focusing properties of super-resolution in the far-field region [1-3]. However, the microstructures used in [1] and [2] have metal wires in an inhomogeneous distribution, which is not beneficial to manufacture and production. In this Letter, we propose one planar sub-wavelength array of super-resolution. Its element interval is as small as 1/20 wavelength. This array can be easily integrated on a printed circuit board, and provides reference for sub-wavelength array design for high-performance mobile terminals.

Investigation of the effects of metal-wire resonators in sub-wavelength array based on time-reversal technique

“…[4][5][6] The same criterion is adopted for probe 2. By comparisons between Figure 4(a) and 4(b), it can be obviously seen that the interference between these two probes have been reduced (reduced from 65% to 6% in the band of 1.0-1.5 GHz and from 66% to 25% in 1.5-2.0 GHz for the peak ratio; the averaged ratio value is reduced from 61% to 6% in the band of 1.0-1.5 GHz and from 68% to 38% in 1.5-2.0 GHz) by loading metal-wire resonators.…”

“…4 Kinds of resonant structures are designed to be loaded around the original source antenna as a special medium to break the diffraction barrier, though the designing method is not a general one. [5][6][7] The resonant meta-lens consisting of metal-wire resonators with equally finite length is one kind of artificial medium with negative permittivity. 8,9 Mathematical studies on super-resolution mechanisms in deterministic complex media 10 show that super-resolution with multiple sub-wavelength resonators 7 could be explained from the modes of resonances with involvement of appropriate asymptotic of the scalar Green function.…”

“…Furthermore, in present literature, the transmission of the signal beyond the diffraction limit can only be achieved at one single antenna (whose signal peak is at least 50% larger than those received by other receiving antennas) element during a communication process. [4][5][6] Thus, a general design method which allows all the sub-wavelength array elements to work simultaneously with little interference is desirable.…”