Space Efficient Meta-Grid Lines for Mutual Coupling Reduction in Two-Port Planar Monopole and DRA Array

Abstract

Traditionally used mutual coupling (MC) reduction techniques such as electromagnetic bandgap structures, isolators and neutralization lines require extra space between radiators. Besides, metamaterial-based techniques require multi-layer arrangements. However, the proposed meta-grid lines overcomes the above demerits by integrating meta-grid lines in the ground plane itself. As a proof-ofconcept, two-port CPW-fed monopole antenna array (TPCFMAA) and two-port DRA array (TPDRAA) are designed, fabricated and tested. It has been observed that the TPCFMAA has mutual coupling below -20 dB for frequency between 2.6 to 4.4 GHz. The envelope correlation coefficient reduces from 0.072 to 0.026 by integrating meta-grid lines in the ground plane of the TPCFMAA. At 3.5 GHz, the inter-element distance between the antennas is noted to be 0.015λ h (λ h = highest operating wavelength). The TPDRAA's operating frequency can be tuned by changing the parameters of the annular ring slot in the excitation patch. The bandwidth of TPDRAA can be further increased by merging the two resonances of the two annular ring slots in the excitation patch. For TPDRAA, the measured -10 dB impedance bandwidth is from 5.65 to 6.55 GHz. The mutual coupling between the antenna elements is seen to be below -16 dB for an inter-element spacing of 4.8 mm, which is 0.090λ h . The measured gain of TPDRAA within the bandwidth is from 4.17 dBi to 5.2 dBi. The TPCFMAA can be used in 3.5 GHz Internet of Vehicles (IoV) multi-user MIMO service, whereas the TPDRAA can be used for satellite communication in the 5.925 to 6.425 GHz frequency band, WiMAX in the 5.7 to 5.85 GHz band, ISM in the 5.725 to 5.85 GHz band, and WLAN in the 5.8 GHz band.INDEX TERMS MIMO antenna, CPW-fed printed monopole antenna array, Cylindrical dielectric resonator antenna (CDRA) array, Single negative (SNG) meta-grid lines.

Diversity Order and Measure of MIMO Antennas in Single-User, Multiuser, and Massive MIMO Wireless Communications

“…The ACC values of two-port CPW-fed monopole MIMO antenna in [21] are tabulated in Table II. As shown in Table II, the DM of this MIMO scheme is highest at 3.52 GHz and lowest at 3.46 GHz.…”

“…Table II: DM of the MIMO system employing the MIMO antenna configuration 2 of [21]: comparison between the ACCbased and Jake's model based methods [22] In order to have an idea about the advantages of the proposed method for calculating the DM based the ACC, existing DM calculation from the correlation coefficient (CC) (𝐶𝐶 = 𝐽 0 ( 2𝜋𝑑 𝑖𝑗…”

Mutual Coupling Reduction in Dual-Band MIMO Antenna Using Parasitic Dollar-Shaped Structure for Modern Wireless Communication

“…In light of these challenges, several MIMO antennas aiming to reduce mutual coupling among closely-deployed antenna radiators for wireless applications are suggested in [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], and [17]. The Ultra-wideband (UWB) antennas in [1] and [2] operating in the 4-12 GHz and 2.95-15.65 GHz bands, respectively, achieved high isolation using Quad G-shaped metamaterial and a parallel strip resonator.…”

“…Nowadays, many researchers are oriented toward designing Dielectric Resonator Antennas (DRA) as these provide several advantages such as higher bandwidth, lower losses (due to the absence of metal), and improved gain and efficiency [10], [11], [12], [13], [14]. Researchers in [10] report an aperture-coupled, fed, two-port DR MIMO antenna built on a Roger's dielectric slab with impedance bandwidth of 4.70-6.20 GHz and a mutual coupling of up to −15 dB operating in the WLAN 5 GHz band.…”

“…Researchers in [10] report an aperture-coupled, fed, two-port DR MIMO antenna built on a Roger's dielectric slab with impedance bandwidth of 4.70-6.20 GHz and a mutual coupling of up to −15 dB operating in the WLAN 5 GHz band. Another two-port DR MIMO antenna mentioned in [11] operates in a single band with a 10-dB impedance between 5.65-6.55 GHz and a mutual coupling of up to −20 dB across the functioning bands. The DR antenna in [12] uses a ring-shaped DR and a defective ground structure to obtain the desired dual-band and uses polarization diversity to improve the isolation among the radiators.…”