**3. Sierpinski carpet wearable fractal antenna**

The construction of Sierpinski carpet fractal antenna is more simple and easy to design. The zeroth iteration, the base shape is a square. In the base shape, the central square is removed to obtain the first iteration. In first iteration geometry, eight squares are left to design the second iteration. This procedure is repeated to obtain next iterations [24]. Furthermore, this antenna is a wearable or body-worn antenna which used Jeans textile as a substrate. Two methods for measuring the dielectric constant (εr) and loss tangent (tanδ) of the Jeans material were presented in this chapter: a microstrip ring resonator method [25, 26] as shown in **Figure 17** and DAK (Dielectric Assessment Kit) method [27]. The results for the two methods are tabulated in **Table 6**. Therefore, use the second method to confirm the results that were selected by using the first one. Also, the thickness of the jeans textile is 0.6 mm which measured by using screw gauge.

## **3.1 Fractal wearable antenna design**

**Figure 18** represents the geometries of the initial, first and second iterations of the Sierpinski carpet fractal wearable microstrip antenna. The optimized dimensions of the presented three antennas are indicated in **Table 7**.

**61**

**Figure 18.**

Value (mm)

**Table 7.**

**Table 6.**

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

*(a) The fabricated ring resonator model, and (b) measured S21.*

**Material The microstrip ring resonator method** Dry jeans **Mode Resonance** 

*Results of the two methods for characterization of jeans textile.*

**Dielectric assessment kit method (DAK)**

*Fractal antenna structures: (a) initial, (b) 1st, (c) 2nd iterations.*

*The optimized dimensions of three iterations antenna.*

**Figure 17.**

The fabricated geometry of the 2nd iterations Sierpinski carpet fractal wearable microstrip antenna is shown in **Figure 19a**. The simulated and measured S11 for the three iterations antennas are shown in **Figure 19b**. Furthermore, the radiation patterns of the proposed fractal antenna in E-plane (Φ = 0°) and H-plane (Φ = 90°) are simulated and plotted in **Figure 20**. From **Figure 19**, Consistent results are

**Wg Lg Wp Lp Wf Lf L1 W1 L2 W2 s**

70 70 50 50 4 10 16 16 8 8 13

**frequency (GHz)**

1.78 0.085

n = 1 4.26 −35.5 1.73 0.077 n = 2 8.89 −36.9 1.69 0.073

**Dielectric constant (εr) Loss tangent (tanδ)**

**S21 (dB)** **Dielectric constant (εr)** **Loss tangent (tanδ)**

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

**Figure 17.**

*Fractal Analysis*

**Figure 16.**

**Table 5.**

**60**

**3. Sierpinski carpet wearable fractal antenna**

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

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

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

1.57 0.232 0.125 2.7 0.607 0.314 3.4 0.632 0.529 5.3 0.347 0.147

which measured by using screw gauge.

**3.1 Fractal wearable antenna design**

The construction of Sierpinski carpet fractal antenna is more simple and easy to design. The zeroth iteration, the base shape is a square. In the base shape, the central square is removed to obtain the first iteration. In first iteration geometry, eight squares are left to design the second iteration. This procedure is repeated to obtain next iterations [24]. Furthermore, this antenna is a wearable or body-worn antenna which used Jeans textile as a substrate. Two methods for measuring the dielectric constant (εr) and loss tangent (tanδ) of the Jeans material were presented in this chapter: a microstrip ring resonator method [25, 26] as shown in **Figure 17** and DAK (Dielectric Assessment Kit) method [27]. The results for the two methods are tabulated in **Table 6**. Therefore, use the second method to confirm the results that were selected by using the first one. Also, the thickness of the jeans textile is 0.6 mm

**1 g 10 g**

**Figure 18** represents the geometries of the initial, first and second iterations of the Sierpinski carpet fractal wearable microstrip antenna. The optimized dimen-

sions of the presented three antennas are indicated in **Table 7**.

*(a) The fabricated ring resonator model, and (b) measured S21.*


#### **Table 6.**

*Results of the two methods for characterization of jeans textile.*

**Figure 18.**

*Fractal antenna structures: (a) initial, (b) 1st, (c) 2nd iterations.*

The fabricated geometry of the 2nd iterations Sierpinski carpet fractal wearable microstrip antenna is shown in **Figure 19a**. The simulated and measured S11 for the three iterations antennas are shown in **Figure 19b**. Furthermore, the radiation patterns of the proposed fractal antenna in E-plane (Φ = 0°) and H-plane (Φ = 90°) are simulated and plotted in **Figure 20**. From **Figure 19**, Consistent results are


**Table 7.**

*The optimized dimensions of three iterations antenna.*

**Figure 19.** *Proposed fractal antenna structures: initial, 1st, and 2nd iterations.*

#### **Figure 20.**

*Radiation pattern in E-plane, H-plane at: (a) 1.7, (b) 5.3, (c) 5.8 GHz.*


**Table 8.**

*Performance simulated results of proposed fractal antenna.*

measured with simulation results. Further, the proposed 2nd iteration Sierpinski carpet fractal wearable microstrip antenna can be used as a multiband antenna. This antenna is operated at three frequency bands in the same time for modern wireless applications as GPS, WiMax and WiFi. The simulation performance results are tabulated in **Table 8**.
