Compact WLAN disc antennas

A novel conical beam patch antenna design, suitable for local area network applications, uses a central cylindrical connection from the disc to ground to achieve a large reduction in resonant size. Results on efficiency, bandwidth, and pattern are reported for several prototypes.     

SAR reduction for handset with two-element phased array antennacomputed using hybrid MoM/FDTD technique

An investigation into a two-element phased antenna array mobile handset using the MoM/FDTD hybrid method is presented. The array is designed to provide a spatial null in the near field zone in the direction of the human head. Compared with an omnidirectional antenna, the overall efficiency and azimuth coverage are improved and the peak specific absorption rate in the head can be reduced by at least 10 dB     

Dual-polarised uniplanar conical-beam antennas for HIPERLAN

A dual-polarised conical-beam microstrip antenna, with a strictly uniplanar conductor pattern, is realised as an array of three square patches whose corners meet a central feed point. For the second polarisation the antenna functions as a series fed array     

Hybrid treatment for electromagnetic field computation in multipleregions

The numerical solution of complex electromagnetic problems via heterogeneous solution methods is proposed. This hybrid method is capable of analysing a system of multiple physically-unconnected regions by employing the principle of equivalent sources. The case of multiple sources in the presence of scattering objects is discussed and the results are compared with other available data     

On the duality between array beam-formers and MU-MISO precoders

Telecommunication Systems - Multi-user transmission, whereby users share time and frequency resources has been an active research area in the past decade in which the uniform linear array (ULA) was...     

A Review of Indoor Localization Techniques and Wireless Technologies

Wireless Personal Communications - This paper introduces a review article on indoor localization techniques and technologies. The paper starts with current localization systems and...     

A hybrid computational electromagnetics formulation for Simulation of antennas coupled to lossy and dielectric volumes

A heterogeneous hybrid computational electromagnetics method is presented, which enables different parts of an antenna simulation problem to be treated by different methods, thus enabling the most appropriate method to be used for each part. The method uses a standard frequency-domain moment-method program and a finite-difference time-domain program to compute the fields in two regions. The two regions are interfaced by surfaces on which effective sources are defined by application of the Equivalence Principle. An extension to this permits conduction currents to cross the boundary between the different computational domains. Several validation cases are examined and the results compared with available data. The method is particularly suitable for simulation of the behavior of an antenna that is partially buried, or closely coupled with lossy dielectric volumes such as soil, building structures or the human body.     

Conduction current crossing domain boundaries in heterogeneoushybrid computational electromagnetics formulation

A heterogeneous hybrid computational electromagnetics method is presented that permits conduction currents to cross the boundary between different computational domains. The method uses a standard frequency-domain moment-method program and the finite-difference time-domain method to compute the fields in the two regions. Several validation cases are examined and the results compared with available data     

Power splitter design for two-element antenna array with high mutual coupling

Design principles for a power splitter driving a strongly coupled two-element handset array antenna have been derived and studied. Splitter circuits using lumped elements and distributed microstrip elements were designed and tested. The results show reasonable agreement between measured and theoretical results.     

A new design of horizontally polarizedand dual-polarized uniplanar conical beam antennas for HIPERLAN

It is shown that a conical beam 5.2-GHz antenna suitable for HIPERLAN application, but working in horizontal polarization, can be realized as a group of microstrip patch radiators in a ring formation. Layouts with three and four patches are described, and radiation patterns are found to agree well with predictions from a simple array model. The three-patch form is smaller and gives a closer approximation to an azimuth-independent pattern. Patterns are very similar to those achieved in vertical polarization with previously reported disk antenna realizations, giving peak radiation at about 50/spl deg/ elevation. Two methods of impedance matching are found to give satisfactory results. A dual-polarized conical-beam microstrip antenna, with a strictly uniplanar conductor pattern, is also presented and realized as an array of three square patches whose corners meet a central feed point. For the second polarization, the antenna functions as a series fed array. Fairly good conical beam patterns have been obtained, though only moderate polarization purity appears to be obtainable from three-element arrays.