Meta-Surface Wall Suppression of Mutual Coupling Between Microstrip Patch Antenna Arrays for THZ-Band Applications

Abstract

This paper presents a novel 2D meta-surface wall to increase the isolation between microstrip patch radiators in an antenna array that is operating in the teraherz (THz) band of 139-141 GHz for applications including communications, medical and security screening systems. The metasurface unit-cell comprises conjoined twin 'Y-shape' microstrip structures, which are inter-digitally interleaved together to create the meta-surface wall. The proposed meta-surface wall is free of via holes and defected ground-plane hence easing its fabrication. The meta-surface wall is inserted tightly between the radiating elements to reduce surface wave mutual coupling. For best isolation performance the wall is oriented orthogonal to the patch antennas. The antenna array exhibits a gain of 9.0 dBi with high isolation level of less than −63 dB between transmit and receive antennas in the specified THz-band. The proposed technique achieves mutual coupling suppression of more than 10 dB over a much wider frequency bandwidth (2 GHz) than achieved to date. With the proposed technique the edge-to-edge gap between the transmit and receive patch antennas can be reduced to 2.5 mm. Dimensions of the transmit and receive patch antennas are 5 × 5 mm 2 with ground-plane size of 9 × 4.25 mm 2 when being constructed on a conventional lossy substrate with thickness of 1.6 mm.

Interaction Between Closely Packed Array Antenna Elements Using Meta‐Surface for Applications Such as MIMO Systems and Synthetic Aperture Radars

“…As well as, the minimum and average mutual coupling suppressions presented by this work show more than 22 and 28 dB improvements compared with Alibakhshikenari et al (2018). Here edge-by-edge distance between the radiation elements is 0.66λ 0 , but in Alibakhshikenari et al (2018) this parameter is 1.16λ 0 . One more point, regarding the different operating frequency bands the antenna arrays have different applications than each other.…”

“…As advantages of the proposed work than Alibakhshikenari et al (2018) we can mention that the maximum mutual coupling suppression here by the proposed technique is 57 dB that shows more than 43 dB improvement than Alibakhshikenari et al (2018). As well as, the minimum and average mutual coupling suppressions presented by this work show more than 22 and 28 dB improvements compared with Alibakhshikenari et al (2018). Here edge-by-edge distance between the radiation elements is 0.66λ 0 , but in Alibakhshikenari et al (2018) this parameter is 1.16λ 0 .…”

Application of metamaterials for performance enhancement of planar antennas: A review

“…In this respect, metasurfaces have been one of the techniques for suppressing mutual coupling between multiple antenna elements. [12][13][14][15]…”

“…Mutual coupling induced by the surface current along the substrate and spatial electromagnetic fields, however, deteriorates the antenna radiation characteristics, and this is one of the major problems for antenna designers. In this respect, metasurfaces have been one of the techniques for suppressing mutual coupling between multiple antenna elements …”

A novel planar antenna array for a ground-based synthetic aperture radar

“…The authors observed higher isolation between the transmitting and receiving antennas when using their novel isolation technique. In [13], the authors were able to achieve a suppression of more than 10 dB using a 2D metasurface wall with microstrip patch antennas. A reduction in the isolation of an airborne SAR system was explored in [14] using a simplified composite right-/left-handed transmission line (SCRLH-TL).…”