A novel ultra-wideband (UWB) monopole antenna suitable to be mounted on the printed circuit board (PCB) of a wireless universal serial bus (USB) dongle as an internal antenna is presented. The proposed antenna in the study is a U-shaped metal plate monopole antenna easily fabricated from bending a simple metal plate onto a foam base of a compact size of 6 x 11 x 20 mm3. The antenna mainly comprises a pair of wide-ended radiating arms and a bevelled feeding transition. When the antenna is mounted at the top portion of the PCB, one end of the radiating arm is also short-circuited to the system ground plane. With the proposed antenna structure, which can provide a very wide operating bandwidth of larger than 7.6 GHz, the antenna’s impedance bandwidth can easily cover the 3.1–10.6 GHz UWB band.

1. 2007 IEEE AP-S
International Symposium
Internal UWB Metal-Plate
Monopole Antenna for a
Wireless USB Dongle
Jui-Hung Chou and *Saou-Wen Su, Ph.D.
Technology Research Development Center
Lite-On Technology Corp., Taipei, Taiwan
*E-mail: stephen.su@liteon.com
Jun 14, 2007

2. Outlines
(I) Introduction
Conventional UWB antennas
Wireless USB scenario (using UWB tech.)
(II) Design Considerations & Results
Constructed prototype
Antenna performance
Parametric studies
(III) Other Promising Studies
Omnidirectional USB-dongle UWB antenna
No-cost printed USB-dongle UWB antenna
(IV) Conclusion
2

3. Conventional UWB Antennas 1
UWB planar monopole antenna
Antenna perpendicular to a large ground plane
Impedance matching controlled by
shaping antenna geometry and/or
adjusting antenna structure around feeding
MOTL, vol 42, Sep 2004 IEEE AP, vol 53, Apr 2005
3

4. Conventional UWB Antennas 2
Numerous UWB planar monopole antennas
in various shapes and sizes
4

5. Wireless USB with UWB Tech.
Home usage scenarios that could be
"unwired" with Wireless USB
Wireless USB: the first high-speed personal wireless interconnect,
5 http://www.intel.com/technology/comms/wusb/download/wirelessUSB.pdf

6. Design Consideration 1-
Configuration of the UWB antenna
Antenna mainly comprises:
a pair of wide-ended
radiating arms and
a bevel-feed transition;
Metal plate onto a foam base
of size 6 x 11 x 20 mm3
6 TW/US Patent Pending

7. Design Consideration 2-
Proposed vs. reference antenna
Corresponding antenna
consists of a rectangular
patch and a bevel-feed
transition;
Antenna volume remains
the same for both
Proposed
Proposed
antenna
antenna
Corresponding simple
Corresponding simple
planar monopole
planar monopole
7

8. Design Consideration 3-
Return-loss performance
10-dB RL BW reaches 7626 MHz
(2984~10610 MHz)
BW: proposed > ref. antenna
(1.6 GHz larger)
8

9. Design Consideration 4-
Measured radiation patterns
Measured radiation
patterns at 5 and 8 GHz
Comparable E-theta and E-phi
components for frequencies
across the UWB band
9

10. Design Consideration 5-
Peak gain and radiation efficiency
Peak antenna gain varies in a range of 3.2-4.6 dBi
across the UWB band;
Mismatch radiation efficiency > 90% due to
use of low-loss, low-permittivity foam base and
antenna protruded from the system ground
10

11. Design Consideration 6-
Parametric studies
Width t of the wide-ended portions
System ground-plane length L
11

12. Promising Studies 1-
Omnidirectional USB-dongle UWB antenna
MOTL, vol 49, Mar 2007
Retractable
Retractable
top casing!
top casing!
12 TW/US Patent Pending

13. Promising Studies 2-
Omnidirectional USB-dongle UWB antenna
Measured radiation
patterns at 5 and 9 GHz
Omni-radiation in x-y
(horizontal) planes
13 TW/US Patent Pending

14. Promising Studies 3-
No-cost printed USB-dongle UWB antenna
10-dB RL BW covers the lower
UWB band 3.1~4.85 GHz (BG1)
0
-10
-20
-30
-40
2.5E+009 3.5E+009 4.5E+009 5.5E+009 6.5E+009 7.5E+009
14 TW/US Patent Pending

15. Promising Studies 4-
No-cost printed USB-dongle UWB antenna
Comparable E-theta and E-phi
radiation patterns;
Peak antenna gain > 1 dBi;
Radiation efficiency > 60%
360
0
270 90
180
15 TW/US Patent Pending

16. Conclusion
Proposed antenna is very easy to
implement by bending a metal plate
into a compact structure
Wide impedance BW of ~7.6 GHz and
good radiation characteristics have
been obtained
More designs of the internal UWB
antennas in wireless USB dongles are
in progress
16

17. THANK YOU FOR YOUR ATTENTION!
17