Planar mesh-lens arrays for millimeter and sub-mm wave focal planes

Traditional focal plane arrays for millimeter and sub-millimeter wave instrumentation are designed using corrugated horn antennas. The next generation of experiments dedicated to the detection of Cosmic Microwave Background (CMB) polarization will require large sensitivities and therefore a large number of pixels in their focal planes. In the context of the technology development for future Cosmic Microwave Background satellite missions, we report the preliminary results of the development of a planar array of small lenses based on the mesh-filter technology.