High-gain bow-tie antenna using array of two-sided planar metamaterial loading for H -band applications

Abstract

A method to significantly increase the gain of a bow‐tie antenna based on metamaterial concept is presented. The μ‐negative feature of the proposed two‐sided planar metamaterial (TSPM) structure is investigated by retrieving its constitutive parameters from the S‐parameters. The proposed structure consists of six slabs that are loaded with a 3 × 3 array of TSPM unit cells, which are embedded in azimuth plane of a modified bow‐tie antenna vertically. The TSPM unit cells provide a medium of low effective permeability. The dimensions of the slabs are 30.6 × 20.6 mm2 at 7 GHz. To show the adaptability of the proposed high‐gain antenna, the structure was designed to cover H‐band applications (6‐8 GHz). Consequently, a small antenna is designed in comparison with initial bow‐tie structures. The corresponding return loss of the antenna is better than 10 dB over 6 to 8 GHz. The proposed metamaterial antenna was manufactured and its characteristics measured to verify the proposed idea. Good agreement between the measured and simulated data is obtained. Maximum gain measured of the antenna is 10.21 dB at 7.5 GHz, constituting a maximum gain enhancement of 7 dB for H‐band in comparison with a bow‐tie antenna without any metamaterial structures.

Gain enhancement and mutual coupling reduction of multiple‐intput multiple‐output antenna for millimeter‐wave applications using two types of novel metamaterial structures

“…As we mentioned in Reference , MPLPM slabs operated as a planar lens that was employed in the azimuth plane of the antenna. To realize the proposed idea, a conventional MIMO antenna, which is reported in Reference , has selected.…”

“…The transfer function ( TF ) is employed to the radiation aperture of the proposed antenna by considering the transmission and the numerous reflections on the air and MPLPM parts. According to Reference , the TF is expressed as: where the parameters of ( t 1 , t 2 ), and ( r 1 , r 2 ) are the transmission coefficients and reflection coefficients of the waves propagated on the air and MPLPM regions, respectively. y 0 and 𝑘 𝑑𝑖𝑒 are the length of the MPLPM medium and dielectric wavenumber, respectively.…”

“…These structures, which were first introduced by Veselago in Reference , have special properties that can be used to increase gain and also reduce the mutual coupling in MIMO antennas . Very recently, the authors have designed a novel high‐gain bow‐tie antenna with the help of metamaterial structures for use in H ‐band applications in Reference . In that paper, with the use of six rotated two‐sided planar metamaterial slabs, the gain of 10.21 dB has been achieved at 7.5 GHz.…”

Planar antenna beam deflection using low‐loss metamaterial for future 5G applications

“…On the other hand, metamaterials (MMs) are engineered periodic microstructures with an unnatural electromagnetic (EM) response—in particular, a negative refractive index. MMs are used in different practical applications such as perfect absorbers and enhance antenna performance . These artificial materials suffer from serious drawbacks such as narrow bandwidth and inherent loss that limit the range of their applications.…”

“…MMs are used in different practical applications such as perfect absorbers 13 and enhance antenna performance. 14,15 These artificial materials suffer from serious drawbacks such as narrow bandwidth and inherent loss that limit the range of their applications. Several techniques have been proposed in the literature to reduce inherent MM loss.…”