A.G. Alhaddad

Folded Loop Balanced Coplanar Antenna for WLAN Applications

A novel balanced rectangular loop antenna is proposed, having an ungrounded coplanar waveguide (CPW) feed configuration and a folded structure at both ends. This antenna is designed for operation over the 2.4 GHz and 5 GHz WLAN frequency bands. Bond-wire bridges are used along the CPW feed line to ensure the same potential across the CPW ground planes. The self-balancing structure that can be realized in a loop antenna offers operation without the need of a separate balun for connection to a RF source. A prototype of the optimized antenna with overall dimension of 31 mm × 16 mm × 3 mm was fabricated and tested. The calculated and measured results show good agreement, confirming good wideband characteristics with multiband operation. An example application of the proposed antenna is studied when used in handheld devices. The results show that this antenna has performance largely independent of perturbations of its associated ground plane, because the balanced feed created by the intrinsic balun structure minimizes ground plane currents.

Design and analysis of UC-EBG on mutual coupling reduction

A new Uniplanar Compact Electromagnetic Bandgap (UC-EBG) structure is proposed in order to achieve a smaller unit cell operating at lower frequency stop band. Its design is detailed and an experimental result is presented. The property of the proposed UC-EBG is compared with the distorted uniplanar compact EBG (DUC-EBG). The application of the proposed UC-EBG is examined. A parametric study on various thicknesses of dielectric substrate is also discussed.

Compact Dual-band Balanced Handset Antenna for WLAN Application

In this paper, a balanced antenna for mobile handset applications with dual- frequency performance, covering the 2.4GHz and the entire 5GHz WLAN frequency bands, is investigated and discussed. The antenna is a thin-strip planar dipole with folded structure and a dual-arm on each monopole. For validation, the antenna prototype was fabricated and tested. The performance of this balanced antenna was verifled and characterised in terms of the antenna return loss, radiation pattern, power gain and surface current distribution of the proposed antenna. The predicted and measured results show good agreement.

A novel dual band tunable balanced handset antenna for WLAN application

This paper presents a tunable balanced antenna covering WLAN frequency bands near 2.4 GHz (2.4–2.4835 GHz) and 5 GHz (5.15–5.35 GHz & 5.650–5.925 GHz), for mobile application. The design is based on loading two variable capacitors onto the planar balanced antenna to electronically tune its resonant frequency; the higher frequency was tuned with the capacitance varying from 0.1pf to 0.3pf, while the lower frequency band remains constant. Performance of the proposed antenna was analyzed and optimized against the two targeted frequency bands. For validation, the antenna prototype was fabricated and tested then the measured results were compared to simulation ones. The performance of this proposed antenna was verified and characterized in terms of the antenna reflection coefficient |S11|, radiation pattern and power gain.

Dual-band balanced handset antenna for WLAN application

A built-in planar metal plate antenna for mobile handsets with balanced operation is presented. The antenna was designed by folding a thin strip planar dipole with extra arm on each monopole. The antenna features balanced operation, is to reduce the current flow on the conducting surface of the handset body. The antenna design model intends to cover 2.4-GHz and the 5.2-GHz WLAN applications. For practical validation, the antenna prototype was fabricated. The measured return loss, radiation pattern and power gain of the prototype antenna are presented to verify the antenna performance. The measured results are found in good agreement with the calculated results.

Interaction between electromagnetic field and human body for dual band balanced antenna using hybrid computational method

This paper describes a hybrid computational method which efficiently models the interaction between a small antenna placed in proximity with the human body. Results for several test cases of placed in different locations on the body are presented and discussed. The near and far fields were incorporated into the study to provide a full understanding of the impact on human tissue. The cumulative distribution function of the radiation efficiency and absorbed power is also provided. The antennas are assumed to be operating over the 2.4 GHz and 5.2 GHz WLAN frequencies.