Gwenn Le Fur

UWB filter-antenna using Spiral Resonator

This paper presents simple and low cost implementations of very wideband antennas using Spiral Resonator (SR) to perform band-rejection filtering within the band. Details on SR design are first given and filter design is then applied on a UWB antenna to filter the WLAN band. Selectivity and performances are observed in terms of impedance matching and efficiencies measurements.

Modal Analysis of Rectangular Waveguides with 2D Metamaterials

A new method to rapidly design 2D metamaterials for rectangular waveguides by rebuilding their dispersion properties is proposed. The Modal Expansion Theory (MET) is revisited for theoretical surfaces with fixed surface impedances ZS . Then, it is pursued for real dispersive anisotropic surfaces, which have surface impedances that are dependent on the frequency and the incidence angle. An algorithm which calculates the correct incidence angle of the guided electromagnetic mode at each frequency is presented. By including this algorithm in the MET and by combining it with a code based on the Finite Element Method (FEM) to calculate the surfaces impedances, dispersion diagrams of waveguides with real 2D anisotropic walls are correctly rebuilt. This is validated by comparing the results for two different metamaterials, corrugationand T-structure, with those obtained using a commercial software.

Comparison of antenna measurement results in disturbed environment using a VHF spherical near field system

This paper presents parts of investigations done in a VHF spherical Near-Field system in order to propose appropriate measurement procedure. First is briefly presented the mono-probe near field system and measurement challenges due to low frequencies. Then is presented the Antenna Under Test (AUT), the antenna pattern comparison approach and the measurement configurations. Finally, several measurement results using two scans configurations are compared to reference simulation result in order to find the most appropriate way of measurement suited to the measurement facility for the large wavelength considered.