*3.1.3 Parametric study*

We are going to play on three parameters, to see its effect on the behavior of this antenna.

• The parameter effect r (RO) (the radius of the radiating part) on coefficient S11 (**Figure 14**) and gain (**Figure 15**):

**85**

S11 parameter:

(**Figure 16**) and gain (**Figure 17**):

*Far-field gain (2D) of circular miniature printed antenna.*

• The parameter effect lg (length of the ground plane) on coefficient S11

Gain:

**Figure 12.**

**Figure 10***.*

**Figure 11.**

*Directivity diagram (3D).*

*Design of a UWB Coplanar Fed Antenna and Circular Miniature Printed Antenna for Medical…*

*DOI: http://dx.doi.org/10.5772/intechopen.93205*

*Gain diagram (3D) of circular patch antenna.*

**Figure 9.** *Gain diagram of circular patch antenna.*

*Design of a UWB Coplanar Fed Antenna and Circular Miniature Printed Antenna for Medical… DOI: http://dx.doi.org/10.5772/intechopen.93205*

#### **Figure 10***.*

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

**Figure 9** gives us the variation of the gain of our antenna as a function of the frequency. It happens to be between 2 and 4.87 dBi on the frequency band which interests us, which is 3.1–10.6 GHz. This limitation of the gain could be improved by

The 3D radiation pattern at the 8 GHz frequency. We can say that the radiation is focused on both sides of the antenna. At the frequency f = 8 GHz the gain of antenna is 4.28 dBi (**Figure 10**) and a directivity of antenna is 4.87 dBi

**Figures 12** and **13** show the far-field gain and far-field directivity in plane E. For both the opening of the main lobe at -3 dB for the frequency 8 GHz is 66.9˚

We are going to play on three parameters, to see its effect on the behavior of this

• The parameter effect r (RO) (the radius of the radiating part) on coefficient S11

**84**

**Figure 9.**

*Gain diagram of circular patch antenna.*

*3.1.2.2 Antenna gain*

**Figure 8.**

*3.1.2.3 Radiation diagram*

(**Figure 11**).

*3.1.3 Parametric study*

[16, 17].

antenna.

a possible networking of antennas [16].

*Return loss of circular miniature printed antenna.*

(**Figure 14**) and gain (**Figure 15**):

*Gain diagram (3D) of circular patch antenna.*

#### **Figure 12.**

*Far-field gain (2D) of circular miniature printed antenna.*

S11 parameter: Gain:

• The parameter effect lg (length of the ground plane) on coefficient S11 (**Figure 16**) and gain (**Figure 17**):

#### **Figure 13.** *Far-field directionality (2D).*

**Figure 14.** *Return loss with effect of the antenna radius.*

**Figure 15.** *Gain diagram with effect of the antenna radius.*

S11 parameter: Gain:

• The parameter effect v (slot location) on coefficient S11 (**Figure 18**) and gain (**Figure 19**):

**87**

*Design of a UWB Coplanar Fed Antenna and Circular Miniature Printed Antenna for Medical…*

*DOI: http://dx.doi.org/10.5772/intechopen.93205*

*Return loss with effect of the length of the antenna ground plane.*

*Gain diagram with effect of length of the antenna ground plane.*

**Figure 16***.*

**Figure 17.**

**Figure 18.**

**3.2 Design of array of circular miniature printed antenna**

We are going to make our antenna network (**Figure 20**) from the previous antenna with some modifications in terms of the parameters and its values in order

*3.2.1 Antenna array geometry*

*3.2.2 Simulation results*

S11 parameter:

to have the desired results (**Table 4**).

*Return loss with effect of the antenna slot location.*

S11 parameter: Gain:

*Design of a UWB Coplanar Fed Antenna and Circular Miniature Printed Antenna for Medical… DOI: http://dx.doi.org/10.5772/intechopen.93205*

**Figure 16***. Return loss with effect of the length of the antenna ground plane.*

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

**86**

S11 parameter:

*Gain diagram with effect of the antenna radius.*

(**Figure 19**): S11 parameter:

• The parameter effect v (slot location) on coefficient S11 (**Figure 18**) and gain

Gain:

**Figure 15.**

**Figure 14.**

**Figure 13.**

*Far-field directionality (2D).*

*Return loss with effect of the antenna radius.*

Gain:

**Figure 17.** *Gain diagram with effect of length of the antenna ground plane.*

**Figure 18.** *Return loss with effect of the antenna slot location.*
