Quad-port MIMO antenna with high isolation characteristics for sub 6-GHz 5G NR communication

Abstract

A four-port MIMO antenna with high isolation is presented. The antenna is primarily envisioned to cover the n48 band of Frequency Range-1 (FR-1) with TDD duplex mode. The engineered antenna has electrical dimensions of 90 × 90 × 1.57 mm3. The size miniaturization of a single antenna unit is achieved through an optimized placement of slots and extended arms. The quad-antennas are then placed orthogonally to achieve antenna diversity. The antenna resonates at 3.56 GHz and 5.28 GHz having 2:1 VSWR fractional bandwidth of 1.82% and 2.12%. The proposed resonator provides 88.34% and 79.28% efficiency at lower and upper bands, respectively. The antenna is an exceptional radiator regarding MIMO diversity performance owing to high inter-element isolation. The values of envelope correlation coefficient < 0.05, channel capacity loss is nearly 0.1 bits/sec/Hz, and total active reflection coefficient is − 24.26. The full ground plane profile aids in high directivity and cross-pol isolation. The antenna exhibits a gain of 4.2 dBi and 2.8 dBi, respectively, justifying intended application requirements. There is a good coherence between simulation and experimental results. The self-decoupled antenna poses its application in 5G and WLAN Communication Applications.

A novel dual-band elliptical ring slot MIMO antenna with orthogonal circular polarization for 5G applications

“…Ref. [ 5 , 6 ] have reported the multi-band MIMO antennas. But the polarization of all the antennas is LP.…”

“… Antenna Elements LP/CP 10-dB Imp. BW (%) Isolation dB (>) 3-dB AR BW (%) Gain (dBi/dBic) ECC (<) [ 5 ] 4 LP 1.82, 2.8 22 – 4.2, 2.8 0.04 [ 6 ] 4 LP 18.7, 14.6 20 – 5.8, 6.2 0.04 [ 14 ] 2 LP, CP 112.1 17 34.4 4.91 0.15 [ 16 ] 2 Dual CP 9.2 33 1.5 5.34 2.6 10 −2 [ 17 ] 4 Dual CP 7.1 19.37 6.3 7.95 2.45 10 −4 [ 18 ] 4 CP 65.0 15 20.1 – 0.01 …”

“…The MIMO antenna consists of two planar inverted-F antenna (PIFA) elements, and the dual-band is realized by designing the slot on the PIFA plate at a minimum current area. A dual-band (operating frequencies are 3.56 GHz and 5.28 GHz) 4-element MIMO antenna has been proposed in [ 5 ]. Different sizes of stubs and slots are included in the single radiating element to achieve multiband.…”

Enhancing gain and isolation of a quad-element MIMO antenna array design for 5G sub-6 GHz applications assisted with characteristic mode analysis

“…However, the architecture has a narrow bandwidth, low gain and a complex structure owing to the use of a decoupling structure to enhance isolation. In 17 , a 2 × 2 MIMO antenna is suggested with measurements of 90 × 90 × 1.57 mm 3 . Since it is a dual band antenna, so it resonates at 3.56 GHz and 5.28 GHz with return loss of – 18 dB and − 23 dB, impedance bandwidth of 0.1 GHz (3.5–3.6) GHz and 0.17 GHz (5.21–5.38) GHz and gain is 4.2 dBi and 2.8 dBi.…”

Dual-Band 2 × 1 Monopole Antenna Array and Its MIMO Configuration for WiMAX, Sub-6 GHz, and Sub-7 GHz Applications

“…The MIMO antenna achieves more than 2.5 dBi peak gain, with more than 15 dB port-to-port isolation. In [15], a novel MIMO antenna with dual-band capability and four ports is discussed. The antenna has two resonance frequencies of 3.56 GHz and 5.28 GHz with bandwidths of 65 MHz and 112 MHz, and gains of 4.2 dBi and 2.8 dBi, respectively.…”