# I-Shaped Metamaterial Using SRR for Multi-Band Wireless Communication
## 8 ISMeTM Array Analysis  
The performance analysis of the ISMeTM unit cell's 1 \(\times\) 2 array, 2 \(\times\) 2 array, and 2 \(\times\) 4 array configurations are presented in this section. The overall dimensions are 10 \(\times\) 20 mm\({}^{2}\), 20 \(\times\) 20 mm\({}^{2}\), and 20 \(\times\) 40 mm\({}^{2}\). To validate the results of the ISMeTM unit cell configuration, the three array configurations are investigated. The Nicolson-Ross-Weir (NRW) is used evaluate the array's effective parameters.  
The schematic diagram of 1 \(\times\) 2 array, 2 \(\times\) 2 array, and 2 \(\times\) 4 array configuration is presented in Figure 7. The arrays are formed by combining two-unit cells horizontally. The S11 and S21 parameters of the array configurations are simulated for the frequency range of 2-18 GHz, and the same approach is used to retrieve their effective parameters.  
In Figure 8a, the S-parameters S\({}_{11}\) (dB) and S\({}_{21}\) (dB) are presented for the three array configurations. The 1 \(\times\) 2 array shows the transmission dips at 6.23, 7.76, 10.10, 10.78, 11.72, 13.36 and 15.5 GHz, which are much closed to the ISMeTM unit cell. The 2 \(\times\) 2 array structure generate transmission minima at frequencies 4.63, 6.05, 6.64, 7.44, 8.12 and 10.4 GHz.  
Figure 7: Schematic diagram of ISMeTM arrays: (**a**) geometry of 1 \(\times\) 2 array; (**b**) simulated model of 1 \(\times\) 2 array; (**c**) geometry of 2 \(\times\) 2 array; (**d**) simulated model of 2 \(\times\) 2 array; (**e**) geometry of 2 \(\times\) 4 array; (**f**) simulated model of 2 \(\times\) 4 array.  
The dips of transmission coefficient \(\mid\)S\({}_{21}\mid\) of 2 \(\times\) 4 array are observed at frequencies 4.69, 5.96, 6.52, 7.30, 7.84, 8.20 and 10.52 GHz. The permittivity of the array configurations is shown in Figure 8b. The SNG frequency ranges for 1 \(\times\) 2 array; 2 \(\times\) 2 array and 4 \(\times\) 4 array are 5.46-6.29, 11.35-11.44, 13.2-14.9, 15.8-16.4; 5.44-6.31, 13.3-13.9, 14.6-15.8, 16.1-16.3 GHz and 5.46-6.28 GHz, 13.6-14.2 GHz, 14.9-15.3 GHz, 15.9-16.4 GHz, respectively. The parameters of various array configurations are summarized in Table 3. The frequency ranges for the parameters in the three array structures are nearly identical to the single unit cell, except variation for a few frequency bands. Due to mutual coupling effect between the array elements, there may be little variation in the array characteristics as compared to the unit cell [42]. In the proposed array, it can be observed that the array arrangements show similarities with the unit cell except for a few frequency bands that changes slightly which is due to the mutual coupling effect between the array elements. This occurs when two or more unit cells are vertically oriented on the \(y\)-axis. However, the arrays still exhibit multi-band properties.  
Figure 8: Parameters of array configurations: (a) S-parameters; (b) permittivity; (c) permeability; (d) refractive index.  
The comparative analysis of the proposed ISMeTM is presented in Table 4. From this table, it can be observed that the proposed ISMeTM is low cost, compact in size and produces seven resonances. The proposed ISMeTM is suitable for multi-band C/X/K-band applications.