Abstract: Disclosed is a substrate particularly designed to bear an active structure made according to thin-film technology. The advantage of the disclosed substrate is that it can be made in large sizes and at low cost. To this end, the substrate 1 has an soda-lime glass plate passivated by means of two superimposed layers. The layer in contact with the glass plate is a barrier layer against the alkaline constituents and the layer deposited on the barrier layer has the function of preventing the effect, on the barrier layer, of the products designed to etch the elements that form the active structure.

Abstract: Disclosed is a microwave load in a small-length oversized waveguide form. It comprises a body in waveguide form, made of an absorbent material with both its ends open. An oversized waveguide propagating low loss microwaves that have to be attenuated is connected to the end of the load. The cross section of the interior of the body is substantially equal to or greater than the cross section of the interior of the oversized waveguide. A mode reflecting and converting device closes the end of the load.