**2. Fractal wearable antenna on metamaterial cell**

#### **2.1 Fractal wearable antenna design**

The simulated geometry of the proposed fractal wearable antenna is illustrated in **Figure 3**. The patch and the ground planes are squares with length = 46 mm, and 70 mm respectively. The substrate is made from FR4 material with thickness h = 1.6 mm, relative permittivity εr = 4.4 and tan (δ) = 0.02.

The inset fed line of the proposed antenna is consisted of two sections: 50 Ω stripline and tapered line for achieving the 50 Ω impedance matching as shown in **Figure 4**. The port dimensions are tabulated in **Table 1**.

The proposed third iteration fractal antenna is designed based on an iteration length, Lm. It is calculated as follows [22]:

Lm = 2Lm + 1 + W1m + 1 + 2W2m + 1 (14).

Where: m is the order of iteration, W1m + 1 = c1Lm; is the width of the middle segment, and W2m + 1 = c2Lm; is the indentation width.

Furthermore, Parameters c1 and c2, are very important parameters for the efficiency of the size reduction [22]. Now, in the presented fractal wearable antenna c1 and c2 are chosen as 0.1 and 0.4 respectively. This antenna is designed to be suitable for operating in GPS, WiFi like Bluetooth, and WiMax frequencies at the time as shown in **Figure 5**.

In addition to, a metamaterial spiral cell is meandered in the ground plane of the presented 3rditeration fractal wearable antenna for enhancement the SAR results (as shown in **Figure 6**). By using this spiral cell, the permeability and the permittivity will be negative, and then the reflection coefficient will be also negative, so that the SAR value is minimized.

**Figure 3.** *The geometry of proposed antenna.*

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**Figure 7.**

*The S11 against frequency for three different iterations.*

*Fractal Antennas for Wearable Applications DOI: http://dx.doi.org/10.5772/intechopen.81503*

*The proposed fractal antenna with different iteration structures.*

**Table 1.**

**Figure 5.**

**Figure 6.**

*Strip-Line Dimensions.*

**2.2 Simulation results**

*The geometry of spiral cell.*

Simulation analysis of the proposed antennas is performed through the commercial software simulator called CST 2016. The simulated S11 for the conventional patch, 1st iteration, 2nd iteration, and the 3rd iteration of the Fractal Wearable Antenna are shown in **Figure 7**. Also, the antenna radiation patterns with/without

**Parameter W1 L1 W2 L2** Value (mm) 3 18.4 8 12

For the four resonance frequency bands, the gain and efficiency are improved by using metamaterial spiral cell. The first band with return loss −23 dB from 1.54 to1.62 GHz, this band is suitable for GPS application. In this band, the gain and efficiency are 2.152 dB and 44.7% and improved with MTM spiral cell to 4.41 dB and 79.1%. The second band with return loss −20.78 dB from 2.67 to 2.87 GHz, this band

spiral cell in E-plane and H-plane are plotted in **Figures 8** and **9**.

**Figure 4.** *The port geometry.*

#### *Fractal Antennas for Wearable Applications DOI: http://dx.doi.org/10.5772/intechopen.81503*


**Table 1.**

*Fractal Analysis*

**2. Fractal wearable antenna on metamaterial cell**

h = 1.6 mm, relative permittivity εr = 4.4 and tan (δ) = 0.02.

**Figure 4**. The port dimensions are tabulated in **Table 1**.

segment, and W2m + 1 = c2Lm; is the indentation width.

length, Lm. It is calculated as follows [22]: Lm = 2Lm + 1 + W1m + 1 + 2W2m + 1 (14).

SAR value is minimized.

*The geometry of proposed antenna.*

The simulated geometry of the proposed fractal wearable antenna is illustrated in **Figure 3**. The patch and the ground planes are squares with length = 46 mm, and 70 mm respectively. The substrate is made from FR4 material with thickness

The inset fed line of the proposed antenna is consisted of two sections: 50 Ω stripline and tapered line for achieving the 50 Ω impedance matching as shown in

The proposed third iteration fractal antenna is designed based on an iteration

Where: m is the order of iteration, W1m + 1 = c1Lm; is the width of the middle

Furthermore, Parameters c1 and c2, are very important parameters for the efficiency of the size reduction [22]. Now, in the presented fractal wearable antenna c1 and c2 are chosen as 0.1 and 0.4 respectively. This antenna is designed to be suitable for operating in GPS, WiFi like Bluetooth, and WiMax frequencies at the time as shown in **Figure 5**. In addition to, a metamaterial spiral cell is meandered in the ground plane of the presented 3rditeration fractal wearable antenna for enhancement the SAR results (as shown in **Figure 6**). By using this spiral cell, the permeability and the permittivity will be negative, and then the reflection coefficient will be also negative, so that the

**2.1 Fractal wearable antenna design**

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**Figure 4.** *The port geometry.*

**Figure 3.**

*Strip-Line Dimensions.*

#### **Figure 5.**

*The proposed fractal antenna with different iteration structures.*

**Figure 6.** *The geometry of spiral cell.*

### **2.2 Simulation results**

Simulation analysis of the proposed antennas is performed through the commercial software simulator called CST 2016. The simulated S11 for the conventional patch, 1st iteration, 2nd iteration, and the 3rd iteration of the Fractal Wearable Antenna are shown in **Figure 7**. Also, the antenna radiation patterns with/without spiral cell in E-plane and H-plane are plotted in **Figures 8** and **9**.

For the four resonance frequency bands, the gain and efficiency are improved by using metamaterial spiral cell. The first band with return loss −23 dB from 1.54 to1.62 GHz, this band is suitable for GPS application. In this band, the gain and efficiency are 2.152 dB and 44.7% and improved with MTM spiral cell to 4.41 dB and 79.1%. The second band with return loss −20.78 dB from 2.67 to 2.87 GHz, this band

**Figure 7.** *The S11 against frequency for three different iterations.*

**Figure 8.** *Radiation pattern in E-plane at (a) 1.57, (b) 2.7, (c) 3.4 (d) 5.3 GHz.*

is suitable for WiMax application. In this band, the gain and efficiency are 1.19 dB and 47.2% and improved to 3.56 dB and 55.54%. The third band with return loss −9.67 dB from 3.33 to 3.46 GHz, this band is suitable also for WiMax application. In this band, the gain and efficiency are 1.112 dB and 56.6% and improved to 2.89 dB

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*Fractal Antennas for Wearable Applications DOI: http://dx.doi.org/10.5772/intechopen.81503*

*simulated return loss S11 with the frequency.*

**Figure 10.**

**Figure 11.**

and 67.45%. The forth band with return loss −8.56 dB from 5.24 to 5.42 GHz, this band is suitable for WiFi application. In this band, the gain and efficiency are

*Fabricated proposed antenna with MTM cell: (a) top and (b) bottom view and (c) the measured and* 

*The fabricated proposed antenna without MTM cell: (a) fabricated geometry, and (b) the measured and* 

The prototypes of the proposed fractal antenna without and with spiral cell and

**Figure 12** shows that the SAR simulation results for the proposed antenna with spiral MTM cell. These results are shown in **Figure 13** and mentioned in **Table 2**. From **Figure 13** and **Table 2**, the intended four bands have a very low SAR value and do not exceed unity. Also, can be notes as the distance between the proposed

In this section, the presented 3rd iteration fractal wearable antenna with MTM spiral cell is used for integration on a floating life jacket. This smart life jacket can be used to help humans get away in the event of an accident [23]. Also, there is another benefit for using that life jacket; it can be used as an isolation cover to prevent the

2.29 dB and 58.5% and improved to 3.38 dB and 68.1%.

the measured S11 for those are shown in **Figures 10** and **11**.

antenna and the human is maximized, the SAR value is minimized.

**2.5 Proposed antenna integrated on life jacket as application**

**2.3 Experimental results and discussion**

*simulated return loss S11 with the frequency.*

**2.4 SAR calculations**

**Figure 9.** *Radiation pattern in H-plane at (a) 1.57, (b) 2.7, (c) 3.4 and (d) 5.3 GHz.*

*Fractal Antennas for Wearable Applications DOI: http://dx.doi.org/10.5772/intechopen.81503*

**Figure 10.**

*Fractal Analysis*

**Figure 8.**

is suitable for WiMax application. In this band, the gain and efficiency are 1.19 dB and 47.2% and improved to 3.56 dB and 55.54%. The third band with return loss −9.67 dB from 3.33 to 3.46 GHz, this band is suitable also for WiMax application. In this band, the gain and efficiency are 1.112 dB and 56.6% and improved to 2.89 dB

*Radiation pattern in E-plane at (a) 1.57, (b) 2.7, (c) 3.4 (d) 5.3 GHz.*

*Radiation pattern in H-plane at (a) 1.57, (b) 2.7, (c) 3.4 and (d) 5.3 GHz.*

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**Figure 9.**

*The fabricated proposed antenna without MTM cell: (a) fabricated geometry, and (b) the measured and simulated return loss S11 with the frequency.*

**Figure 11.**

*Fabricated proposed antenna with MTM cell: (a) top and (b) bottom view and (c) the measured and simulated return loss S11 with the frequency.*

and 67.45%. The forth band with return loss −8.56 dB from 5.24 to 5.42 GHz, this band is suitable for WiFi application. In this band, the gain and efficiency are 2.29 dB and 58.5% and improved to 3.38 dB and 68.1%.

## **2.3 Experimental results and discussion**

The prototypes of the proposed fractal antenna without and with spiral cell and the measured S11 for those are shown in **Figures 10** and **11**.

#### **2.4 SAR calculations**

**Figure 12** shows that the SAR simulation results for the proposed antenna with spiral MTM cell. These results are shown in **Figure 13** and mentioned in **Table 2**. From **Figure 13** and **Table 2**, the intended four bands have a very low SAR value and do not exceed unity. Also, can be notes as the distance between the proposed antenna and the human is maximized, the SAR value is minimized.

#### **2.5 Proposed antenna integrated on life jacket as application**

In this section, the presented 3rd iteration fractal wearable antenna with MTM spiral cell is used for integration on a floating life jacket. This smart life jacket can be used to help humans get away in the event of an accident [23]. Also, there is another benefit for using that life jacket; it can be used as an isolation cover to prevent the

water reaching the proposed antenna. The simulated life jacket with voxel model is shown in **Figure 14**, and the dimensions with some electrical characteristics of that simulated life jacket are tabulated in **Table 3**.

**Figure 12.**

*SAR distribution at (a) 1.57, (b) 2.7, (c) 3.4 and (d) 5.3 GHz.*

**Figure 13.** *Maximum SAR values by two standard: (a) FCC, and (b) ICNIRP.*


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shown in **Table 4**.

are shown in **Table 5**.

The simulated S11 for the presented wearable fractal antenna with and without the floating life jacket are shown in **Figure 15**. Furthermore, the simulated performance results for the intended antenna with the simulated floating life jacket are

**Resonance frequency (GHz) Gain (dB) Efficiency (%)** 1.57 1.11 67.3 2.7 2.89 51.2 3.4 1.65 62.3 5.3 2.42 63.4

*The simulated life jacket attached to the proposed antenna with voxel model: (a) front and (b) top views.*

**Layer type Rubber Air** Layer thickness (mm) 1.9 20 Dielectric constant (εr) 3 1 Tangent loss (σ) 0.0025 0.002

*Dimensions of simulated life jacket with some electrical characteristics.*

*Simulated S11 for the presented antenna with/without life jacket.*

*The simulation results of the proposed antenna with life jacket.*

By using the floating life jacket is as an isolation cover for the presented antenna, the SAR value is also improved as shown in **Figure 16**. The SAR simulation results

*Fractal Antennas for Wearable Applications DOI: http://dx.doi.org/10.5772/intechopen.81503*

**Figure 14.**

**Table 3.**

**Figure 15.**

**Table 4.**

**Table 2.**

*Max. SAR values for the proposed antenna with spiral cell.*

**Figure 14.**

*Fractal Analysis*

**Figure 12.**

**Figure 13.**

simulated life jacket are tabulated in **Table 3**.

*SAR distribution at (a) 1.57, (b) 2.7, (c) 3.4 and (d) 5.3 GHz.*

*Maximum SAR values by two standard: (a) FCC, and (b) ICNIRP.*

*Max. SAR values for the proposed antenna with spiral cell.*

**Resonance frequency (GHz) SAR (W/kg)**

1.57 0.452 0.237 2.7 1.02 0.925 3.4 0.67 0.384 5.3 0.75 0.249

**1 g 10 g**

water reaching the proposed antenna. The simulated life jacket with voxel model is shown in **Figure 14**, and the dimensions with some electrical characteristics of that

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**Table 2.**

*The simulated life jacket attached to the proposed antenna with voxel model: (a) front and (b) top views.*


**Table 3.**

*Dimensions of simulated life jacket with some electrical characteristics.*

#### **Figure 15.**

*Simulated S11 for the presented antenna with/without life jacket.*


#### **Table 4.**

*The simulation results of the proposed antenna with life jacket.*

The simulated S11 for the presented wearable fractal antenna with and without the floating life jacket are shown in **Figure 15**. Furthermore, the simulated performance results for the intended antenna with the simulated floating life jacket are shown in **Table 4**.

By using the floating life jacket is as an isolation cover for the presented antenna, the SAR value is also improved as shown in **Figure 16**. The SAR simulation results are shown in **Table 5**.

#### **Figure 16.**

*SAR with life jacket at (a) 1.57, (b) 2.7, (c) 3.4, (d) 5.3 GHz.*


**Table 5.**

*Max. SAR values for the proposed antenna with the life jacket.*
