**5. Conclusion**

*UWB Technology - Circuits and Systems*

**14**

**Ref.** Ref [17] Ref [20] Ref [21] Ref [22] Ref [14] Ref [23] Ref [15] Ref [24] Ref [25] Ref [26] Proposed

40 × 40 × 0.40

13/15/16/141/16/11

2.1/3.3/3.5/3.9/2.2/4.2

96.7/92.7/94.2/74.4/95.8/91.2

6

antenna

**Table 2.**

*Comparison of propose designed with those in the state-of-art literature.*

2018

30 × 24.8 × 1.6

3.5/5.01/13.2/5.77

1.35/1/1.07/1.75

—

4

2018

40 × 40 × 1.6

11.49/3.37/8.61

2017

50 × 50 × 1.6

2/12/18.2

2017

40 × 40 × 1.6

1.9/14/5

2016

48 × 48 × 1.6

20.73/15.02/31.96

1.64/2.07/4.06

−4.5/3.75/5.3 6.35/5.57/3.9 1.78/3.5/4.4

2015

55 × 50 × 1.9

25.3/16.95/12.32

5.71/6.16/6.48

79/86.6/88.7 66.2/77.15/87.6

10/91/87 82.1/84.9/90.9

75.62/72/73

3

3

3

3

3

2015

56 × 44 × 0.8

5.56/5.86/19.34/13.69

1.3/2.3/3.5/4.4

2014

40 × 40 × 1.6

34.48/18.28/19.96

3.97/4.04/3.25

2013

52.6 × 30 × 1

47.27/38.88

−0.56/−0.62

89.2/98.1

—

76.8/80.1/96.6/85.5

4

2 3

2013

49 × 49 × 6

2.63/3.28/6.44

4.93/2.85/5.12

89.9/91.8/97.6

**Year**

**Antenna size** 

**Bandwidth (in %)**

**Gain (in dBi)**

**Radiation efficiency (in %)**

**No. of** 

**Covered wireless standards**

**Frequency Band** 

**Reconfigurability** 

**Achieved**

**operating** 

**modes (in** 

**GHz)**

3

GPS/WLAN/WiMAX

No

(1.52/2.44/3.57)

GPS/WLAN (1.5/2.4)

(WLAN/WiMAX (2.4/3.5/5.8)

GPS/WLAN/WiMAX

(1.5/2.4/3.5/5.4)

(WLAN/WiMAX (2.4/3.5/5.8)

GPS/WLAN (1.9/2.4/5)

(GPS/WLAN/WiMAX (1.5/3.5/ 5.4)

(WLAN/ X Band) (4.8/5.8/9.2)

(WLAN/ WiMAX Band) (2.4/3.5/

5.5)

(WiMAX/X Band)

No

(3.1/5.52/7.31/9.72)

WLAN/WiMAX/WiFi/UWB/

Yes

ISM Band/Radar Application Band

(2.4/5.2/5.8/3.1–10.6/2.45/9.2)

No

No

No

No

No

No

No

No

**(in mm3**

**)**

A frequency band reconfigurable antenna suitable for WLAN (2.4/5.2 GHz). ISM band (2.4–2.5 GHz), WiMAX (2.3–2.4 and 5.15–5.85 GHz), WiFi (2.40–2.48 and 5.15–5.85 GHz) and UWB (3.1–10.6 GHz) wireless standards are presented in this chapter. Proposed design also covers the airborne radar applications works at 9.2 GHz. The radiating element of octagonal shape and switchable slotted ground is implemented to achieve the frequency band reconfigurability between wireless standards. The switching between the narrowband, dual band and UWB modes is obtain by using five p-i-n diodes placed inside the inverted L shaped ground slot. The proposed design is provides the facility of easily integration with cognitive radio and multi radio wireless terminal devices. Proposed design achieve the bandwidth of 16% (5.05–5.89 GHz) and 14% (5.01–5.79 GHz) in simulation and measurement mode respectively for narrowband states I. Next it obtained bandwidth of 11% (8.76–9.80 GHz) and 10% (8.68–9.69 GHz) in simulation and measurement mode respectively for narrowband states II. Antenna resonant in dual band mode and achieve impedance bandwidth of 13% (2.21–2.52 GHz) and 15% (5.07–5.89 GHz) under simulation and 12% (2.20–2.50 GHz) and 15% (5.05– 5.90 GHz) during measurement for next state III. For next state IV, antenna identifies the operating bandwidth of 14% (2.18–2.52 GHz) and 10% (8.78–9.71 GHz) and 13% (2.19–2.50 GHz) and 9% (8.70–9.60 GHz) during simulation and measurement mode respectively. For UWB mode of V state, antenna indicate the operating bandwidth of 141% (2.87–16.87 GHz) and 140% (2.97–16.80 GHz) under simulation and measurement mode respectively. The average gain of 3.9 dB is achieved for UWB mode of the proposed antenna. The radiation efficiency is stay above the 70% in all the narrow band, dual band and UWB band. Radiation characteristics of the proposed antenna are achieved with good impedance matching at these resonant frequencies. The radiation pattern, gain and efficiency are consistent over all the operating bands making the proposed antenna a good choice for wireless applications.
