08-05-2012, 12:38 PM
Design of an Ultrawideband Monopole Antenna for Portable Radio Transceiver
[attachment=21542]
INTRODUCTION
THE recent expansion of wireless communications has
seen a growing interest in the design of compact multiband
and wideband antennas. Such antennas are required for
portable radio transceivers to access various wireless services
that are predominantly available in the 880 MHz–5.85 GHz
frequency band. These include GSM, GPS, DCS, PCS, UMTS,
WLAN, and WiMAX. The commercial market demands a
compact single-feed antenna to work with a radio transceiver
to cover these service bands. The design of such an antenna is
very challenging [1]–[3]. The result of this challenge is that the
antenna traditional 10-dB return loss is often replaced by 6 dB
in the manufacturer’s specification [1], [2]. The other important
specification is to have an omnidirectional pattern across the
operational band.
ANTENNA CONFIGURATIONS
A. Unfolded Geometry
Initially, the unfolded antenna is designed with the use of CST
Microwave Studio 2009. Its configuration is shown in Fig. 1.
Its dimensions are found from initial design guidelines [6]
followed by manual iterations. A parametric analysis is applied
to obtain an insight into this antenna performance.
A quarter-ellipse planar monopole with major axis of
mm and minor axis mm is located on the top layer
of a 1.6-mm FR4 substrate having a dielectric constant of 4.4.
RESULTS AND DISCUSSION
A photograph of the antenna manufactured on a 1.6-mm FR4
substrate is shown in Fig. 5.
Fig. 6 shows both the simulated and measured results for
the input reflection coefficient of the folded monopole antenna.
Close agreement between the measured and simulated results is
observed in the targeted frequency range.
Simulated 2D normalized radiation patterns of the proposed wideband
antenna at several frequencies used by modern wireless services.
The measured results show that the antenna covers an ultrawide
frequency band between 850 MHz up to 6 GHz at
the 6-dB return loss or VSWR 3:1. As a result, the proposed
antenna can cover all the popular wireless services including
GSM, GPS, DCS, PCS, UMTS, WLAN, and WiMAX. This
UWB coverage shows potential of the proposed antenna for use
in modern portable multiband transceivers.
[attachment=21542]
INTRODUCTION
THE recent expansion of wireless communications has
seen a growing interest in the design of compact multiband
and wideband antennas. Such antennas are required for
portable radio transceivers to access various wireless services
that are predominantly available in the 880 MHz–5.85 GHz
frequency band. These include GSM, GPS, DCS, PCS, UMTS,
WLAN, and WiMAX. The commercial market demands a
compact single-feed antenna to work with a radio transceiver
to cover these service bands. The design of such an antenna is
very challenging [1]–[3]. The result of this challenge is that the
antenna traditional 10-dB return loss is often replaced by 6 dB
in the manufacturer’s specification [1], [2]. The other important
specification is to have an omnidirectional pattern across the
operational band.
ANTENNA CONFIGURATIONS
A. Unfolded Geometry
Initially, the unfolded antenna is designed with the use of CST
Microwave Studio 2009. Its configuration is shown in Fig. 1.
Its dimensions are found from initial design guidelines [6]
followed by manual iterations. A parametric analysis is applied
to obtain an insight into this antenna performance.
A quarter-ellipse planar monopole with major axis of
mm and minor axis mm is located on the top layer
of a 1.6-mm FR4 substrate having a dielectric constant of 4.4.
RESULTS AND DISCUSSION
A photograph of the antenna manufactured on a 1.6-mm FR4
substrate is shown in Fig. 5.
Fig. 6 shows both the simulated and measured results for
the input reflection coefficient of the folded monopole antenna.
Close agreement between the measured and simulated results is
observed in the targeted frequency range.
Simulated 2D normalized radiation patterns of the proposed wideband
antenna at several frequencies used by modern wireless services.
The measured results show that the antenna covers an ultrawide
frequency band between 850 MHz up to 6 GHz at
the 6-dB return loss or VSWR 3:1. As a result, the proposed
antenna can cover all the popular wireless services including
GSM, GPS, DCS, PCS, UMTS, WLAN, and WiMAX. This
UWB coverage shows potential of the proposed antenna for use
in modern portable multiband transceivers.