Metasurface Cloaks to Decouple Closely Spaced Printed Dipole Antenna Arrays Fed by a Microstrip-to-Balanced Transmission-Line Transition

Abstract

In this work, we present a numerical study of 1D and 2D closely spaced antenna arrays of microstrip dipole antennas covered by a metasurface in order to properly cloak and decouple the antenna arrays operating at neighboring frequencies. We show that the two strongly coupled arrays fed by a microstrip-to-balanced transmission-line transition are effectively decoupled in 1D and 2D array scenarios by covering the dipole antenna elements with an elliptically shaped metasurface, which comprises subwavelength periodic metallic strips printed on an elliptically shaped dielectric cover around the dipole antennas and integrated with the substrate. We present a practical design of cloaked printed dipole arrays placed in close proximity of each other and demonstrate that the arrays are decoupled in the near field and operate independently in the far field with their original radiation characteristics as if they were isolated.INDEX TERMS Antenna arrays, beam steering, elliptical metasurface, mantle cloaks, microstrip-tobalanced transmission-line transition, mutual coupling, phased arrays.

Decoupling and Cloaking of Tailored Complementary Cloaked Antennas

“…As expected, the cloaked CPDA and CGCSA antennas adequately radiated power at their cloaked frequencies but poorly radiated power at their cloaked frequencies. These results are in good agreement with the cloaking effects observed in previous studies [1]- [4], [7].…”

“…A cloak is formed through interactions within the layers [17]- [18]. However, practical applications are difficult [1]- [4] [6]- [7] because guided wave cloaks occupy substantial volumes through which cloaked waves are detoured [12]- [16]. Additionally, the high dielectric and conduction losses reduce efficiency.…”

“…Mantle cloaking involves an ultra-thin metasurface [1]- [8]. Such cloaking is based on scattering cancellation by a superthin metasurface surrounding the target [1]- [4]. The mechanism is electrical; the cancelling field is induced by anti-phase metasurface currents.…”

“…Mantle cloaking in the microwave region has been intensively studied; elliptical metasurfaces were used to surround bare metallic monopole or dipole antennas in [1] and wideband cloaked antennas in [2]. These studies were then extended to interleaved antenna arrays with the antenna elements in close proximity and operating at neighboring frequencies [4], [7]- [8]. The performance of cross-coupled, printed, monopole antenna arrays surrounded by elliptical metasurfaces was explored in [8], whereas the performance of printed dipole antenna was explored in [7]; interference caused by the radiations of adjacent antennas was eliminated.…”

Cloaking of Equilateral Triangle Patch Antennas and Antenna Arrays with Planar Coated Metasurfaces

“…As part of recent works, at microwave frequencies, the mantle cloaking method has been used to decouple and cloak interleaved arrays of two monopole antennas [ 41 , 42 , 43 , 44 ], and in [ 45 ], a solution for minimizing the electromagnetic interference among multiple monopole antennas in a restricted space is presented. It is further protracted to 1D and 2D configurations of microstrip dipole arrays [ 46 ]. A method to improve the cloaking performance of a wideband mantle cloak is presented in [ 47 ].…”