Jean-Marc Laheurte

CPW-Fed Slot Antennas on Multilayer Dielectric Substrates

CPW-fed slot antennas printed on multilayer dielectric substrates are numerically analyzed using a full-wave integral technique and the method of moments. The excitation of surface waves in millimeter wave slot-antennas is limited by using an appropriate combination of substrates and slots. A twin-slot antenna and a small array of slots built on optimized stacked subtrates are analysed from the study of the distribution of power between the radiated field and the surface modes.

antennes microrubans passives et actives alimentées par guide d’ondes coplanaire

Un modele numerique base sur la resolution d’equations integrales couplees est utilise pour la conception d’antennes microrubans alimentees par guide d’ondes coplanaire. On montre que les caracteristiques de ces antennes sont similaires a celles d’antennes alimentees par ligne microruban a travers une fente. Des antennes oscillantes et des antennes a large bande passante travaillant en bande C sont realisees en utilisant le modele theorique. Differentes formes de la fente d’excitation sont envisagees et il apparait qu ’une fente en anneau est bien adaptee a l’integration d’elements actifs.

Backing of microstrip patch antennas fed by coplanar waveguides

A microstrip antenna fed by a conductor-backed coplanar waveguide is demonstrated. The addition of a back-side metallic ground plane involves a possible leakage of the CPW mode into Parallel Plate Modes (PPMs) or the excitation of these PPMs by the back-radiation of the coupling slot. A theoretical model, based on the solution of coupled integral equations, is validated by experimental results. It is shown that the power leakage can be avoided by a proper choice of the substrate characteristics.

A CPW-Fed Active Microstrip Antenna Working in the C-Band

The design and performance of a CPW-fed microstrip antenna integrated directly with a FET amplifier are presented. The SWR of the passive antenna is less than 1.6 on a 21% bandwidth. Crosspolarisation levels below 20 dB are measured in both E and H-plane. An extra-gain of 6 dB at 5.25 Giz is obtained by adding the FET amplifier to the passive antenna.