Pei Cheng Ooi

A Dual-Band Circular Slot Antenna with an Offset Microstrip-Fed Line for PCS, UMTS, IMT-2000, ISM, Bluetooth, RFID and WLAN Applications

In this paper, a circular slot antenna fed by an ofiset microstrip-fed line is proposed. The antenna exhibits dual-band characteristics. The two operating frequency bands are: 1.83{2.73GHz and 5.36{7.63GHz, which are of impedance bandwidth 39.5% and 34.9% respectively. The bands are suitable for PCS, UMTS, IMT- 2000, ISM, Bluetooth, RFID and WLAN applications. A parametric study has been carried out by varying the location of the feedline to investigate its efiect on the resonant frequency. Impedance, radiation and gain characteristics of the proposed antenna are also presented and discussed.

THE EFFECT OF GROUND PLANE ON THE PERFORMANCE OF A SQUARE LOOP CPW-FED PRINTED ANTENNA

The efiect of shaping the ground plane on the performance of a square loop coplanar waveguide (CPW)-fed printed antenna is reported in this paper. Experimental results are presented on the re∞ection coe-cient and radiation pattern of the investigated antennas. Simulation results are presented on the current distribution, input impedance and gain. It is observed based on the results that shaping the ground plane signiflcantly afiects the re∞ection coe-cients, input impedances and current distributions.

The effect of different structures of embroidery patch antenna on polymer substrate with identical embroidery properties

This paper presents a novel class embroidery patch antenna on polymer composite - polydimethylsiloxane (PDMS). By lamination and polymer integration, different structures of fully embroidered polymer patch antenna with ground plane have been designed, fabricated and tested. Analysis of the effect of conductive patch weight, conductive characteristics using different embroidery structure on antenna performance has been carried out. The measured results show that although double embroidered layer on one side of fabric has similar conductivity and identical embroidery properties as two-sided embroidery, the antenna performs better using two-sided embroidery structure.

A dual-band CPW-fed printed square loop antenna for wireless applications

A simple square loop printed antenna fed by a coplanar waveguide (CPW) is proposed. Considering a return loss criterion of better than 9.5 dB, the antenna operates in two frequency bands: 1.73–2.50 GHz and 3.44–3.87 GHz. These bands represent 36.4% and 11.8% impedance bandwidths respectively. A parametric study has also been carried out by varying the spacing between the ground and the square loop to investigate its effect on the resonant frequency. Properties of the proposed antenna are studied through simulation and are experimentally verified. The operating frequency bands of the antenna are able to support PCS 1.85–1.99 GHz, UMTS 1.92–2.17 GHz, IMT 1.9–2.2 GHz, ISM 2.4–2.484 GHz and WiMAX 3.49–3.79 GHz bands.

Compact T-Shaped CPW-fed printed antenna for 3.5 GHz WiMAX applications

This paper demonstrates a simple and compact CPW-fed T-shaped printed antenna for WiMAX 3.5 GHz applications. A prototype has been designed, fabricated and tested. The measured results show that the operating frequency of the antenna is from 3.26 GHz to 4.28 GHz for a return loss of better than −10 dB. Satisfactory radiation patterns have also been obtained through simulation.

A novel V-shaped CPW-FED printed antenna for WLAN/WiMAX applications

A novel and compact V-shaped printed antenna is proposed for 5.2/5.8 GHz WLAN and 5.5 GHz WiMAX applications. A prototype is fabricated and measured. The antenna offers a return loss of better than ¿10 dB from 5.15 to 6.06 GHz. Satisfactory radiation pattern is obtained through simulation.

Empirical Equations for the Resonant Frequencies of a Dual-Band Microstrip Loop Antenna [Antenna Designer's Notebook]

Empirical formulas are presented for predicting the resonant frequencies of a coplanar-waveguide-fed dual-band microstrip loop antenna. The resonant frequencies predicted by the formulas compared with experiments with an average error of about 1.85%.

Investigation of embroidery conductive layer dyed with graphene and ZnO

This paper presents a method to improve the conductivity of embroidered patch antenna by using graphene and zinc oxide (ZnO) nanopowder. By dispersion and immersion of graphene and ZnO, the embroidered conductive patch layers have been designed, fabricated and tested. Analysis of the effect of graphene and ZnO solution on patch resistance has been carried out. The measured results show that the conductivity performs better with ZnO dyed embroidered patch layer. In contrast, graphene improves the sheet resistance while ethanol solvent reacts with silver thread.