Gain:

*Advanced Radio Frequency Antennas for Modern Communication and Medical Systems*

which is [2.7 10.6 GHz] [18].

*Gain diagram with effect of the antenna slot location.*

In **Figure 21,** we see that the coefficient S11 is of the order of −42 dB for a resonant frequency of 6.08 GHz, we obtained exactly the bandwidth that interests us,

**Parameter** *r Lm wm tm lg wp lp s u v g k* mm 9 7 1.5 0.035 6 4 9 12 1.8 13 0.18 5

**88**

**Figure 21.**

*Return loss of array antenna.*

**Figure 20.**

**Figure 19.**

**Table 4.**

*Antenna array structure.*

*Dimensions of the array antenna.*

**Figure 22** gives us the variation of the gain of our antenna as a function of the frequency. Note that the gain has increased to 7.6 dBi on the frequency band [3.1– 10.6 GHz]. This networking of antennas has allowed us to increase the gain [19].

At the frequency of 6.14 Hz in **Figure 23** (Gain Diagram) and **Figure 24** (Directivity Diagram), we can say that the radiation is focused on both sides of the

**Figure 22.** *Gain diagram of array antenna.*

**Figure 23***. Gain diagram of array antenna.*

**Figure 24.** *Directivity diagram.*

*Advanced Radio Frequency Antennas for Modern Communication and Medical Systems*

antenna but this time we have side lobes. With a gain of 6.7 dBi and a directivity of 7.6 dBi at f = 6.14 [20, 21].

Radiation diagram:

**Figures 25** and **26** show respectively the far-field gain and far-field directivity in plane E. The opening of the main lobe at -3 dB for the frequency 6.14 GHz is 32.8˚ [22–25].
