sses and efficiency can be predicted in some way. It could also be beneficial in identifying the equivalent circuit model of the antenna. The simulated and the measured Z-parameter plot of the proposed MIMO antenna is shown in Figure 11.3. 11.4.1.3 Antenna to Antenna Isolation This antenna to antenna separation is a measure of how closely two antennas are coupled. Antenna isolation is typically evaluated for antennas within the same product, such as the separation between a smartphone's GPS and WiFi antenna. The isolation should be as large as possible when provided in this manner. At the low band, isolation can be as low as -10 dB or less for antennas that share a similar ground plane, such as primary cellular antennas and the diversity on a smartphone. The efficiency of both antennas will suffer as a result of isolation. The simulated and the measured isolation plot of the proposed MIMO antenna is shown in Figure 11.4. 11.4.2 FAR-FIELD PARAMETERS FOR MIMO ANTENNAS In the following subsection, the far-field parameters of the proposed compact 4-Port MIMO antenna construction include the terms 3-D Polar Plot, and gain that are discussed in depth. 5G Wireless Communication System in Healthcare Informatics Frequency (GHz) Frequency (GHz) FIGURE 11.2 (a) Reflection coefficient of Port 1, (b) Reflection coefficient of all Ports. MIMO Antennas for loT and ISM Band Z11 11 (re) Z, 11 (im) Z, 22 (re) Z. 22 (im) Z33 33 (re) Z3 (im) Z 44 (re) Z, 44 (im) Frequency (GHz) FIGURE 11.3 Z-Parameter of the proposed antenna. S (4,1) S (1,2) S (3,4) S (2,3) Freq (GHz) FIGURE 11.4 Isolation of the proposed antenna. 5G Wireless Communication System in Healthcare Informatics 11.4.2.1 3D Polar Plot The polar plot is a plot that depicts the transfer function of the system G(j)) on a complex plane in polar coordinates. The polar plot representation depicts a plot of magnitude against phase angle in polar coordinates with variation in W from 0 to 80. The simulated and the measured 3-D polar plots of the proposed MIMO antenna are shown in F