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This paper presents compact S-band and X-band antenna products dedicated to CubeSat applications and their radio frequency performances. The S-band antenna covers simultaneously the 2.025–2.110 GHz telecommand and the 2.2–2.29 GHz telemetry band. It has a hemispherical radiation pattern with superior gain and lower axial ratio values at low elevation angles compared to other S-band antennas on the market. On the other side, the X-band antenna is optimized for payload TM at the frequencies 8.025–8.4 GHz. The antenna gain is higher than 10 dBi over ± 10° in all planes and the axial ratio is excellent. Both antennas are smaller than a 1 U surface and have unequalled RF performances. All processes and materials have strong space heritage and benefit from the Cnesadvanced label. These antennas are thus perfectly suited for professional CubeSat missions with high level of performance and reliability.

This paper is an application and an evolution of the new technology that has been already used for a GNSS L1 patch antenna. This technology allows the design of miniature antennas consisting of ceramic material manufactured with an additive process. Based on a patented technology, the dielectric material is structured with a 3D lattice design to obtain the desired effective permittivity. Two different lattices have been studied in this paper which are applied to a miniature circularly polarized dielectric resonator antenna (DRA). Simulated results are given and discussed.

The modal theory for propagation in structures with constant anisotropic surface impedances as a boundary condition is developed for cylindrical waveguides and rectangular waveguides with vertical anisotropic surfaces. Dispersion diagrams for these waveguides are computed for various sets of surface impedances. The results are then validated by comparison, using commercial software. These results confirm a number of interesting properties of such waveguides with anisotropic surface impedances: the cutoff frequency can be drastically lowered, and left-handed mode propagation in a given frequency band can be obtained. The development of this theory can open the door to the development of new design tools for various applications using guided structures such as small waveguides, filters, positive phase shifters, or horns with excellent radiation properties.

This article presents a new analytical approach to calculate very rapidely the field distribution in rectangular waveguides with anisotropic walls.

A new approach to design a metamaterial surface (meta-surface) with the objective of reducing the waveguide's cutoff frequency of the fundamental mode is proposed. From an analytical study of the dispersion diagrams of waveguides with anisotropic walls, a hypothesis for the surface impedances is set up. By means of this new hypothesis, the design of a unit-cell is optimized. Finally, the periodically arranged meta-surface is implemented in a miniaturized waveguide and the simulation results are compared to the ones of a metallic waveguide in order to validate the approach.

International audience; Dans cet article, une nouvelle méthode pour la reconstruction des propriétés de dispersion de guides rectangulaires à métamatériaux 2D est proposée. Un al-gorithme qui estime l'angle d'incidence correct du mode électromagnétique guidé à chaque fréquence est présenté. Cette approche est validée en comparant les résultats d'une structure anisotrope 2D avec ceux obtenus sous un logiciel commercial.