High-Performance Ultra-Wideband Planar Antenna Design

High-Performance Ultra-Wideband 

Planar Antenna Design 

翁金輅(Kin-Lu Wong) 

國立中山大學電機系 

Dept. of Electrical Engineering 

National Sun Yat-Sen University 

Kaohsiung, Taiwan 

E-mail: wongkl@ema.ee.nsysu.edu.tw 

1

Wireless Communication 

Systems and Standards 

NSYSU, Taiwan 

2

Operating Systems and 

UWB Planar Antennas 

NSYSU, Taiwan 

n UWB, short-range communications, 3.1~10.6 GHz 

Systems with BW > 1.5 GHz or > 25% 

n WMAN (IEEE 802.16a, fixed wireless, 2~11 GHz; 

IEEE 802.16e, mobile wireless, 2~6 GHz) 

n UWB access-point (AP) antennas 

n Planar metal-plate monopole antennas 

n Printed monopole antennas 

n UWB antennas for mobile units 

n UWB mobile phone antennas (internal or stubby 

monopole) 

n UWB internal laptop antennas 

3

UWB AP Antennas- 

NSYSU, Taiwan 

Planar metal-plate monopoles (1) 

2:1 VSWR BW larger than 10 GHz (covering 

3.1~10.6 GHz or 2~11 GHz) can be obtained 

4


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Planar metal-plate monopoles (2) 

Considerations of UWB radiation characteristics: 

(1) Vertical polarization purity (suppressing horizontal currents) 

(2) Stability of omni radiation pattern across the UWB band 

5


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Planar monopoles and quasi-dipoles 

6

NSYSU, Taiwan 

UWB/802.16a AP Antenna- 

Square planar monopole with notches (1) 

BW: 10.7 GHz (2.0~12.7 GHz), 10 dB RL 

0 

-10 

-20 

-30 

-40 

1E+009 5E+009 9E+009 1.3E+010 

7

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Notch: w = 7 mm, h = 3 mm, d = 1.5 mm 

Unmarked curves: Measured 

Marked curves: Simulated 

Simulated 3D pattern (HFSS) 

8

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Simulated 3D pattern (HFSS) 

9

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10

UWB AP Antenna- 

Square planar monopole with 

trident-shaped feeding strip (1) 

BW: 10 GHz (1.4~11.4 GHz), 10 dB RL 

Improved BW and polarization purity 

-10 

-20 

-30 

Feeding strip type 

Trident strip 

Two-branch strip 

Simple strip 

0 

NSYSU, Taiwan 

-40 

0 3E+009 6E+009 9E+009 1.2E+010 

t, h, d (mm) 

15, 3.5, 1.0 

15, 3.5, 1.0 

---, ---, 2.5 

BW, f L ~ f U (GHz) 

10.1, 1.4 ~ 11.5 

8.8, 1.4 ~ 10.2 

1.9, 1.4 ~ 3.3 

f U /f L 

8.2 

7.3 

2.3 

11




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Measured radiation patterns at 2 and 6 GHz 

12




Measured radiation patterns at 10 GHz 

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Gain: 4-7 dBi across the band 

13


Step-shaped planar monopole (1) 

BW: 4.4 GHz (2.2~6.6 GHz), 2:1 VSWR 

Improved omni pattern across the band 

d = 2 mm 

0 

-10 

-20 

NSYSU, Taiwan 

-30 

1E+009 2E+009 3E+009 4E+009 5E+009 6E+009 7E+009 

Azimuthal pattern 

14


Step-shaped planar monopole (2) 

Good omni pattern across the band 

NSYSU, Taiwan 

Measured radiation patterns at 3 and 6 GHz 

15


U-shaped planar monopole 

BW: 5.1 GHz (2.0~7.1 GHz), 2:1 VSWR 


0 

-10 

-20 

NSYSU, Taiwan 

-30 

1E+009 3E+009 5E+009 7E+009 9E+009 

0 

-10 

-20 

L = 25 mm, W = 11 mm, 

t = d = 4 mm 

-30 

1E+009 3E+009 5E+009 7E+009 9E+009 

16


Cylindrical planar monopole (1) 

BW: 4.7 GHz (1.9~6.6 GHz), 2:1 VSWR 


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A cross patch used for fabricating the antenna 

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Cylindrical planar monopole (2) 

Gain variations < 1.5 dB across the band 

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Cross-plate monopole 

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BW: ~10 GHz (1.8~11.9 GHz), 10-dB RL 


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Tri-plate monopole 

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BW: ~10 GHz (2.7~12.9 GHz), 10-dB RL 


0 

-10 

-20 

-30 

1E+009 4E+009 7E+009 1E+010 1.3E+010 

20

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Band-notched UWB planar monopole (1) 

By incorporating a suitable (slot or slit) structure to be a half-wavelength at the 

desired notched frequency, a destructive interference could take place, causing the 

UWB antenna non-responsive at that frequency -- Band-notched characteristic 

25 

20 

15 

10 

5 

0 

2E+009 4E+009 6E+009 8E+009 1E+010 1.2E+010 

BW covering 3.1 ~ 10.6 GHz with a 

notched frequency band at 5 GHz 

21

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Band-notched UWB planar monopole (2) 

Slot length = 2L + W -2t 

L = 11 mm, W = 9 mm, t = 2 mm 

Slot length = 27 mm ~ 0.5l at 5.5 GHz 

25 

20 

15 

10 

5 

0 

2E+009 4E+009 6E+009 8E+009 1E+010 1.2E+010 

L = 11 mm 

22

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Band-notched UWB circular monopole 

BW covering 3.1 ~ 10.6 GHz, with the 

notched frequency band controlled by 

the slot length 

15 

10 

5 

0 

1E+009 4E+009 7E+009 1E+010 1.3E+010 

15 

10 

5 

0 

1E+009 4E+009 7E+009 1E+010 1.3E+010 

23


Band-notched UWB slot antenna 

BW covering 3.1 ~ 10.6 GHz, with the 

notched frequency band controlled by 

the U-slot length in the tuning stub 

10 

8 

6 

4 

2 

NSYSU, Taiwan 

0 

2E+009 4E+009 6E+009 8E+009 1E+010 1.2E+010 

24

UWB Printed Antenna- 

Diversity printed monopoles 

BW: 5.4 GHz (2.3–7.7 GHz), 10 dB RL; 

Good port isolation (S21 < –20 dB) 

across the band; 

Gain: about 3.5 dBi in 2.4/5.2/5.8 GHz 

bands 

0 

-10 

-20 

-30 

-40 

-50 

-60 

2E+009 3E+009 4E+009 5E+009 6E+009 7E+009 8E+009 

PCMCIA card 

NSYSU, Taiwan 

25

NSYSU, Taiwan 

UWB Mobile Phone Antenna- 

Internal metal-plate monopole 

BW: 6 GHz (1.9~7.9 GHz), 10 dB RL 

Suitable for UMTS/WLAN (2.4/5.2/5.8 GHz) operations 

26

NSYSU, Taiwan 

UWB Mobile Phone Antenna- 

Stubby cylindrical monopole 

Antenna comprises an upper hollow conducting cylinder 

and a lower conducting cone 

BW: 8.8 GHz (1.8~10.6 GHz), 10 dB RL 

Suitable for UMTS/WLAN (2.4/5.2/5.8 GHz) 

operations or UMTS/UWB operations 

27

UWB Laptop Antenna- 

Shorted planar monopole 

BW: ~4 GHz (2.1~6.0 GHz), 10 dB RL 

W = 36 mm, L = 14 mm, t = 3 mm 

NSYSU, Taiwan 

28

Conclusion 

NSYSU, Taiwan 

n UWB planar antennas for accesspoints 

and mobile-units applications 

have been presented 

n Planar antennas are good 

candidates for UWB communication 

applications 

29

Thanks for Your Attention! 

NSYSU, Taiwan 

30

High-Performance Ultra-Wideband Planar Antenna Design

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