  We report the design, fabrication and testing of Lumped Element Kinetic
Inductance Detectors (LEKID) showing performance in line with the requirements
of the next generation space telescopes operating in the spectral range from 80
to 600 GHz. This range is of particular interest for Cosmic Microwave
Background (CMB) studies. For this purpose we have designed and fabricated
100-pixel arrays covering five distinct bands. These wafers have been measured
via multiplexing, where a full array is read out using a single pair of lines.
We adopted a custom cold black-body installed in front of the detectors and
regulated at temperatures between 1 K and 20 K. We will describe in the present
paper the main design considerations, the fabrication processes, the testing
and the data analysis.
