# Eight Element Wideband Antenna with Improved Isolation for 5G Mid Band Applications
## 4 Proposed Eight-Element Antenna
### Conformal Analysis  
Conformal analysis is one of the primary research areas related to the flexible MIMO antenna. The antenna characteristics tend to change when it is bent relative to different applications involving continuous bending and crumpling of the antenna [4]. As displayed in Figure 13, the suggested antenna is curved at a 50 mm radius over the x (vertical) and y (horizontal) axes. The antenna shows a slight deviation in its resonant frequency for both axis of the bend. It is important to note that the antenna still retained its bandwidth, proving that it offers a superior bending profile.  
The CST Studio EM tool was used to model the bending of the antenna, and a 50 mm-radius cylindrical Styrofoam was used to validate the antenna results. The simulated bending results of the suggested antenna are displayed in Figure 14a-d. For brevity only, a few simulated scattering parameter results are shown. The antenna maintained both its transmission and reflection coefficients even after the bending circumstances, as seen in the picture. The measured scattering parameters of the proposed antenna under both bending scenarios are given in Figure 15a-d. The antenna gave a bandwidth of 4.48-5.6 GHz and 4.53-5.48 GHz for the x (vertical) and y (horizontal) axes, respectively, with a minimum isolation of 20 dB throughout the operational range as shown in Figure 15. Figure 16a,b analyses the proposed antenna's co- and cross-polarization radiation characteristics in the principal planes (E and H) under both the x (vertical) and y (horizontal) axis bends calculated for the resonant frequency of 5.03 GHz. The figure indicates that the radiation characteristics remained excellent even after bending, hence validating the suggested eight-element antenna's suitability for conformal applications.  
Figure 12: Simulated scattering parameters using HFSS and equivalent circuit model (**a**) reflection coefficient; (**b**) transmission coefficient.  
Figure 13: Conformal analysis of the proposed antenna along the \(x\)-axis (vertical) and \(y\)-axis (horizontal) bend.  
The effect of antenna deformation on MIMO parameters such as ECC, DG, MEG, and ME due to both \(x\)-axis bending scenarios are displayed in Figure 17.  
The effect of antenna deformation on MIMO parameters such as ECC, DG, MEG, and ME due to both \(y\)-axis bending scenarios is displayed in Figure 18.  
Figure 14: Simulated scattering parameters under x (vertical) and y (horizontal) bending scenarios: (**a**) reflection coefficient \(x\)-axis (vertical) bend; (**b**) transmission coefficient \(x\)-axis (vertical) bend; (**c**) reflection coefficient \(y\)-axis (horizontal) bend; and (**d**) transmission coefficient \(y\)-axis (horizontal) bend.  
Figure 15: _Cont._  
Figure 16: Effect of bending on radiation properties (at 5.03 GHz): **(a)** E-plane (co- and cross-polarization); **(b)** H-plane (co- and cross-polarization).  
Figure 15: Measured scattering parameters under bending scenarios: (**a**) reflection coefficient \(x\)-axis (vertical) bend; (**b**) transmission coefficient \(x\)-axis (vertical) bend; (**c**) reflection coefficient \(y\)-axis (horizontal) bend; and (**d**) transmission coefficient \(y\)-axis (horizontal) bend.  
Figure 17: Effect of \(x\)-axis bending on MIMO parameters: (**a**) ECC and DG; (**b**) ME; and (**c**) MEG.  
Figure 18: Effect of \(y\)-axis bending on MIMO parameters: (**a**) ECC and DG; (**b**) ME; and (**c**) MEG.