*4.1.1 Analysis of results and interpretation*

The results obtained must be compared with those which have already been the subject of research and accepted in the scientific research community (**Table 4**).

Comparing our works to those listed, it is clear that our obtained gain is greater than the proposed works, the bandwidth obtained is better compared to the works [11, 18]. The reflection coefficients obtained are better compared to works [16, 15] but the bandwidth obtained in these works is better than ours. We can therefore deduce from these works that our antennas comply with and meet the requirements imposed by 5G technology.

### **4.2 Amplifier case**

After modeling the amplifier, it is therefore important to observe the parameters obtained by the amplification after simulation. The S-parameters of the amplifier are summarized in **Figure 20** below.


#### **Table 4.** *Comparative analysis at the antenna level.*

**Figure 20.** *S-parameters of the amplifier without stage transistor.*

The S-Parameters of the amplifier with stage transistor are shown in **Figure 21** below.

As we notice in our figures above the amplifier presents 04 parameters namely S11, S22, S12, S21 the parameters S11, S22 respectively represent the reflection coefficients at the input and at the output of the amplifier and the parameter S12 represents isolation, the parameter S21 represents the amplifier transmission gain. The goal of making a transistor stage is therefore to improve the transmission gain of the amplifier. The **Table 5** below illustrates the characteristics of the amplifier.

The following table establishes a comparison between our work and the work carried out by [19] (**Table 6**).

Our results obtained in simulation are much better than that obtained in [19]. Our amplifier has a gain of 15 dB which shows that our amplifier meets the requirements imposed by 5G technology.
