Dual‐band CPW fed MIMO antenna with polarization diversity and improved gain

Abstract

A dual‐band MIMO slot antenna with polarization diversity and improved gain is proposed in this article. The antenna is composed of two C‐type back‐to‐back connected slot resonators and offers resonances at 3.5 and 5.2 GHz. This antenna element is further used to design a MIMO antenna. By introducing one U‐shaped slot between two antenna elements, isolation between the ports of this MIMO antenna is improved further. Finally, an artificial magnetic conductor (AMC) is placed below the MIMO antenna to enhance its gain. Gain enhancement of 1.5 and 2.2 dB is achieved at lower and upper band, respectively. S‐parameters, radiation patterns, gain, envelope correlation coefficient, and channel capacity loss are investigated to conclude about its performances in MIMO applications. Dual band dual polarization (circular and linear), improved isolation, polarization diversity (right‐hand circular polarization and left‐hand circular polarization), gain enhancement all are presented in a simple design represents the novelty of the proposed MIMO antenna.

Design and implementation of a compact tri‐band four‐port multiple‐input‐multiple‐output antenna

“…The ground planes of the antenna elements were unconnected in References 23,24. In comparison to previously reported MIMO antennas, 7–25 the prospective MIMO antenna has the following advantages: The four‐port MIMO antennas investigated in the literature have single or dual‐band operation, whereas the prospective antenna has triple‐band operation. The triple‐band operation is achieved without the use of a parasitic radiator/element or multi‐layering. In comparison to previously antenna designs, the developed MIMO antenna exhibits a higher level of inter‐element isolation. The proposed MIMO antenna is easy to manufacture as it is a unilayer module. The antenna has a very small overall footprint when compared to other reported designs, making it suitable for modern communication devices. …”

“…The MIMO antennas presented in References 11,13 were two-port designs with single and dual-band operation. The ground planes of the antenna elements were unconnected in References 23,24. In comparison to previously reported MIMO antennas, [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] the prospective MIMO antenna has the following advantages:…”

“…The isolation was improved when a CSRR/SRR unit cell was placed between the antenna elements in 13–15 . Numerous two‐port MIMO antenna designs with meta‐structures for isolation were proposed in 16–21 . A two‐element MIMO antenna with the triple‐band operation was investigated in Reference 22 In References 23,24, four‐port MIMO antennas comprised of parasitic elements were developed, but they were relatively bigger in size and only operated in one band.…”

“…[13][14][15] Numerous two-port MIMO antenna designs with meta-structures for isolation were proposed in. [16][17][18][19][20][21] A two-element MIMO antenna with the triple-band operation was investigated in Reference 22 In References 23,24, four-port MIMO antennas comprised of parasitic elements were developed, but they were relatively bigger in size and only operated in one band. In Reference 25, a four-port MIMO antenna with dual-band operation was presented.…”

Bandwidth and gain enhancement of triple‐band MIMO antenna incorporating metasurface‐based reflector for WLAN/WiMAX applications

“…There are different methods to lower down the mutual coupling in MIMO antennas such as DGS loadings [6], neutralisation lines [7, 8], split‐ring resonator loadings [9, 10], parasitic configuration loading [11], antennas with multilayer configurations [12, 13], frequency selective surfaces [14, 15], electromagnetic bandgap structures [16], and substrate integrated waveguide [17]. Also, the gain and bandwidth of the MIMO antennas are enhanced by artificial magnetic conductor loadings [18, 19], Fabry Perot metamaterial (MTM) superstrates [20], multilayer metasurface (MS)‐based superstrate [21], MTM inspired hexagonal ring based superstrate [22], epsilon and Mu near to zero MTM superstrates [23], MTM‐based superstrate [24], crossed‐dipole antenna with a small frequency separation ratio applicable for MIMO systems [25], crossed dual‐polarised and dual‐band bowtie dipole antenna combined with an AMC‐based reflector [26], dual‐band MIMO slot antenna with dual‐band AMC loadings [27], and dual‐band MIMO based four‐port array antenna with filtering structures [28]. The above‐explained multilayer antenna designs acquire higher antenna dimensions and larger antenna profile with more design complexity.…”