Compact MIMO antenna with high port isolation for triple‐band applications designed on a biomass material manufactured with coconut husk

Abstract

A compact two-element multiple-input multiple-output (MIMO) antenna is proposed for triple-band applications with very high port isolation. The structure is constructed in-house with a flexible biomass material which is coconut husk. Two metallic "8"-shaped antenna structures are employed manually on the substrate to serve as MIMO elements. Frequency bands of the antenna for (S 11 ≤ −10 dB) are obtained from 2.04 to 2.51 GHz, 4.43 to 5.35 GHz, and 6.76 to 8.78 GHz. The antenna fulfills the wireless local area network (WLAN) (2.4-2.485/5.15-5.35 GHz), fixed-mobile (4.45-5.15 GHz), and International telecommunication union (ITU) (8-8.5 GHz) application bands. A stub with three subsections is integrated in the ground to improve the overall triple-band port isolation characteristics. It is found that the minimum port isolation for entire application bands is greater than 20 dB. This low correlation between the elements is further confirmed by low value of envelope correlation coefficient (ECC < 0.14) and high value of diversity gain (DG > 9.98 dB). Channel capacity loss (CCL < 0.22 bit/s/Hz) and mean effective gain (MEG = ±0.19 dB) are also found within acceptable ranges. Characterization of the substrate material of the proposed MIMO antenna is rigorously investigated by analyzing its dielectric constant and loss tangent. Simulated and measured results ratify that the antenna is fit for triple-band MIMO applications.

Fabrication of Cellulose Powder Dielectric Composite Material using Pineapple Leaves Fiber

“…In contrast, synthetic fibers, which are costlier and nonbiodegradable, contribute significantly to electronic waste generation [3]. A wide variety of plant-based sources, including banana leaves, coconut husks, palm kernel shells, oil palm fronds, sugarcane bagasse, rice husks, carrot waste, residues from the production of apple juice, coffee residues, and pineapple leaves, provide abundant natural fibers [4][5][6][7][8][9][10]. Among these, pineapple leaves, often discarded as waste after harvesting the fruit, boast promising chemical composition and mechanical properties that can be harnessed to produce valuable natural fibers [7].…”

Asymmetrical fed Calendula flower-shaped four-port 5G-NR band (n77, n78, and n79) MIMO antenna with high diversity performance

“…There can be different configurations of the MIMO antenna (2 × 2, 4 × 4) which are designed for specific applications and ensure good isolation between them. The MIMO antennas [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] discuss the design methodology and isolation techniques used so that the interference between the neighboring radiators' field radiation is mitigated and hence, all the required results are preserved. A square patch with rectangular ground placed orthogonally maintains isolation of more than 30 dB [1] while a T-type stub attached to the ground between two adjacent radiators [2,3,12] and a tapered feed patch MIMO antenna [4,8] observes better isolation by using rotated L-type strips.…”

“…In an F-shape inverted antenna, a Swastik-shaped repetitive etched structure is applied to improve the isolation [9], and a short stub-loaded resonator with added T-shaped junction in between dual radiating patch [10] and novel elliptical type stub in-ground helps in achieving higher [11]. A unique pair of fractal stub [13, 15, 16] multiband MIMO antenna with a T-shaped stub on the ground [14] and the dual half-cut quasi self-complementary MIMO antenna utilizes no complex decoupling structure for isolation [17]; feather-type circular-shaped loaded radiator achieves isolation by placing the two identical radiators orthogonally or adjacent to each other [18, 19] and a T-type stub etched with semicircular slot also helps in maintaining higher isolation between two radiating elements placed adjacent to each other [20]. The above-discussed MIMO antenna is of 2 × 2 configuration and also different techniques are applied to achieve better isolation in a four-port MIMO configuration.…”

Design of a triple band notched polarization independent compact FSS at UWB frequency range

“…A triple band multiple-input-multipleoutput (MIMO) antenna is implemented using biomass as a substrate to cover WLAN (5.15-5.35 GHz), fixed mobile (4.45-5.15 GHz), and ITU (8-8.5 GHz) application bands. 3 Lower WiMAX, middle WiMAX and WLAN are obtained as transmission bands using a simple antenna design. 4 In multi-band antenna systems, the interference within the system can occur due to poor isolation in between closely separated frequency bands and can also disrupt the functioning of the devices working at frequency bands other than the aforementioned ones over the UWB range.…”