Mohammed Serhir

A Low-Profile Cavity-Backed Dual-Polarized Spiral Antenna Array

A low-profile cavity-backed dual-polarized printed spiral antenna array is presented. This spiral array is composed of four center-fed Archimedean spiral antennas printed on FR4 substrate backed by a low-profile cavity without absorbing material. The dual polarization is generated using monopolarized spirals in an alternating configuration right-hand circularly polarized (RHCP) and left-hand circularly polarized (LHCP). These spirals are connected allowing the current to flow from the excited spirals arms into the arms of the neighboring ones. The proposed spiral array provides unidirectional beam while being dual-polarized (LHCP or RHCP) for a wide bandwidth. The dual polarization of the proposed spiral array is extended to low frequencies, and the gain varies up to 13 dBi in the antenna bandwidth. The antenna array performances are presented and validated using electromagnetic simulations and radiation pattern measurements.

A cavity-backed dual polarized array of connected spiral antennas

A connected array of spiral antennas with dual polarization and backed by a cavity is presented. A 5-elements array is measured using a simple, yet efficient, feeding technique. A low profile cavity is used to make the radiation unidirectional. First measurements show a good agreement between simulations and measurements.

Development of pulsed antennas measurement facility: Near field antennas measurement in time domain

This paper focuses in the construction of a new near-field antenna measurement facility in Electromagnetic Research Department of Supelec dedicated to pulsed antennas characterization. The planar near-field measurement data are exploited through near-field to near-field or near-field to far-field transformation algorithms to determine the antenna radiation pattern in the different spatial areas. The measurement system is described and the results of the experimental validation of the developed algorithms are depicted.

Antenna characterization from arbitrary near field measurement geometry

A method is presented for computing far-field pattern of an antenna under test (AUT) from its near-field measurements taken over an arbitrary geometry (for example hemi sphere). The mathematical formalism and the stability of this method are presented. The effect of reduced signal to noise ratio is studied. The proposed method has been implemented using Matlab software. The numerical validations using analytical radiating model and electromagnetic software results show the efficiency and the stability of the proposed technique.