Characteristic mode analysis of two port semi‐circular arc‐shaped multiple‐input‐multiple‐output antenna with high isolation for 5G sub‐6 GHz and wireless local area network applications

Abstract

The work presents the design of a novel semi-circular arc-shaped two-element multiple-input-multiple-output (MIMO) antenna with improved isolation. The antenna is obtained by cutting and subtracting a circular disk from another circular disk, forming the shape of a semi-circular arc. The antenna is replicated to form a two element MIMO antenna system on a FR4 substrate of size 36 Â 26 mm 2 with edge-to-edge separation of 12.4 mm. The developed MIMO antenna resonates in the frequency range 3.26 to 6.97 GHz giving a maximum element-to-element isolation around 26 dB in the operating bandwidth. Also, the antenna gives a maximum radiation efficiency of 98% with a peak gain of 5.3 dBi in the operating band. The proposed compact MMO antenna covers wide variety of wireless applications like 5G sub-6 GHz and wireless local area network (WLAN) applications, which includes n77/n78/n79, WiFi-5, V2X/DSRC, WiFi-6, and INSAT-C bands. Characteristic mode analysis (CMA) is performed in characterizing the performance of the antenna over the specified operating bands by studying and analyzing the parameters like modal significance (MS), characteristic angle (CA), modal current, and modal patterns. The obtained MIMO parameters like envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), and total active reflection coefficient (TARC) reveal that the proposed antenna is a suitable choice in MIMO environment.

Design of novel compact eight‐element lotus shaped UWB‐MIMO antenna with triple‐notch characteristics on hollow substrate

“…The simulated ECC values are found in good agreement with the measured values. The ECC for the two-element MIMO antenna is represented in Equation ( 7) [37,38]. Another significant parameter describing the diversity performance of the antenna is diversity gain (DG), which is characterised as the increase in signal-to-interference ratio due to some diversity scheme, or how much the transmission power can be reduced when a diversity scheme is introduced, without a performance loss.…”

A detailed insight of 2 × 2 high isolation wideband dual notched band MIMO antenna with evolution initiated by theory of characteristics mode

“…The challenges encountered in designing these antennas have fuelled the advancement in the field of the antenna due to reasons such as the need for antennas with smaller physical size, lower weight, and cost, multi-wideband bandwidths, the capability of reconfigurable, etc. Therefore, the breakthrough in designing these antennas has emerged in the form of the TCMs [28][29][30] which gives freedom to analyze the physics behind the key attributes including bandwidth polarization and distribution of surface current density (SCD) on a patch of antenna and ground. The theory behind TCM is older than 50 years which was proposed by Garbacz in 1965.…”

“…High rejection triple notched band UWB-X band is achieved on high permittivity dielectric substrate with permittivity 11.2 [27]. CMA analysis is carried out by using 7-modes which achieves n77/n78/n79 bands [28], and assymetrical Calendula-shape radiating patch also exhibits of achieveing three bands [29]. The modal analysis is applied to sloteed anteena [30] for UWB applications with the use of 5-modes.…”

An inverted U‐shaped merged stubs hexa‐band 4‐element MIMO antenna for advanced wireless applications

“…This simple design configuration supports an efficiency of 91% with a gain of 2.75 dBi. Similarly, a lower‐profiled printed MIMO antenna for 5G‐smartphone new radio in Biswas and Gupta, 6 an antenna‐array with two‐bands for 5G compact smartphone areas in Wei and Feng, 7 a quad‐port MIMO system using rejection band based on LPF in El‐Hameed et al, 8 a four element compact planar structure MIMO system with similar characteristics of radiations in Li et al, 9 a miniaturized four‐element printed MIMO system for ISM‐band region in Kaboutari and Hosseini, 10 a kotch fractal compact‐UWB system with band‐rejection in Tripathi et al, 11 a slotted‐edge compact four‐port MIMO system with two‐bands rejection in Raheja et al, 12 a MIMO antenna system using DGS approach for interference inherent in Babu et al, 13 a MCP loaded reflector four‐port UWB system for LTE‐WiMAX and Bluetooth with improved performance in Mohanty and Sahu, 14 a four‐port compact isolator of MMLC fractal loop and coupling resonator with Wi‐Max rejection in Mohanty and Sahu, 15 a monopole using thin‐inductive of line‐resonator enhancing bandwidth and isolation in Tan et al, 16 a compact QSC diversity/MIMO with rejection of band of dual‐polarized system in Zhu et al, 17 a two‐port MIMO system for the 5G portable in Chattha, 18 an eight‐element array for dual‐band MIMO 5G in Yan et al, 19 a slotted four‐port compact ground truncated structure MIMO system for 5G lower sub‐6 GHz in Mohan et al, 20 a wang‐shaped structure neutralization line for improvement of isolation in Babu and Anuradha, 21 a four‐port compact super wide‐band MIMO system with characteristics of triple band in Raheja et al, 22 a slot integrated/inverted‐F four element system for WLAN access points in Liao et al, 23 a four‐element dual notched band antenna with multi‐tone suppression of interference for IR UWB applications in Shehata et al, 24 a miniaturized MIMO antenna development and design using parasitic elements with ML technique in Babu et al, 25 a four‐port MIMO system using EBG structure with band notched characteristics in Wu et al, 26 a quad‐band high isolation MIMO antenna for WLAN areas in Liu et al, 27 a four‐port compact quasi‐elliptical super wideband MIMO with elimination characteristics of dual‐band in Raheja et al, 28 a four‐port compact MIMO radiator using CSRR in Kumar et al, 29 a circular shaped UWB system for improved isolation in Addepalli et al, 30 a quad‐port low profile UWB system using DGS technique in Pannu and Sharma, 31 a two‐port CMA analysis semi‐circular MIMO system for 5G and WLAN applications in Addepalli et al, 32 a meander line‐shaped pentaband four‐element MIMO for applications in mobile satellite services,...…”