ine's max- imum to minimum voltage. In actuality, any feeder or transmission line will experi- ence a loss. To calculate the VSWR, forward and reverse power are detected at that 5G Wireless Communication System in Healthcare Informatics W1 (3mm) W1 (5mm) Frequency (Ghz) W1 (3mm) W1 (5mm) Frequency (GHz) FIGURE 11.9 (continued) MIMO Antennas for loT and ISM Band location on the system and transformed into a VSWR figure. The voltage maxima and minima do not need to be determined along the length of the line because the VSWR is measured at a specific place. Figure 11.10 depicts the VSWR of all of the antenna's ports. W1 (3mm) W1 (5mm) Frequency (GHz) W1 (3mm) W2 (5mm) Frequency (Ghz) FIGURE 11.10 (a-d) VSWR of all ports of the proposed antenna. 5G Wireless Communication System in Healthcare Informatics W1 (3mm) W1 (5mm) Frequency (GHz) W1 (3mm) W1 (5mm) Frequency (GHz) FIGURE 11.10 (continued) MIMO Antennas for loT and ISM Band TABLE 11.1 Simulation parameters Number Isolation Efficiency DG of Ports (mm³) Bandwidth (GHz) 2.2 GHz to 5 GHz 3.1 Ghz to 7 GHz <0.04 2.36 GHz to 12 GHz 3 GHz to 11 Ghz [23] 2018 46 X 46 <-17 <0.02 40 X 40 2.3 GHz to 8.8 GHz [25] 2015 38.5 X 2.5 GHz to 12 GHz [26] 2014 40 X 40 - <0.005 2.2 GHz to 13.3 GHz 8-9.5 [27] 2021 48 X 48 <0.04 2.5 Hz to 5 GHz 50 X 82 <-15 <0.02 3 GHz to 9 GHz 40 X 30 2.2 GHz to 4.25 GHz 58 Note: P.S = proposed structure; DG = Directive Gain; ECC = Envelope correlation coefficient'. PERFORMANCE COMPARISON In terms of size, isolation between antenna elements, ECC, operating bands, effi- ciency, and DG, Table 11.1 compares the planned compact four-port MIMO antenna array to different existing MIMO systems. The proposed 4-port MIMO antenna has a wide impedance bandwidth, modest dimensions, and excellent ECC and DG values, as indicated in the table. 11.6 CONCLUSION Antennas with pattern diversity for multiple input multiple output (MIMO) are critical technology for modern mobile communication systems that enable excellent spectrum efficiency. The size of the device, which