Abstract: In order to interconnect an unprotected bare chip of MMIC (microwave monolithic integrated circuit), a ceramic substrate carries a double-face circuit. A network of microstrip lines which radiate from the center to the periphery is disposed on the first face of said double-face circuit. The bare MMIC chip and its microwave environment is fixed on the second face which is metallized as a ground plane. The microwave circuit is interconnected with the network of microstrips by means of plugged metallized holes. A sole-piece provided with a housing for the MMIC is fixed on the ground plane. The first face can carry self-protected components.

Abstract: A method for the welding by laser, of two metallic parts having a clearance between them. This method is characterized by a dual laser discharge operation. A first laser discharge, done with a first offset with respect to the lateral face of one part, melts a strip of metal which comes into contact with the metal of the other part. A second laser discharge, done with a second offset, smaller than the first offset, heats the two parts and forms a weld joint.

Abstract: An ultra high frequency circuit constructed in hybrid or integrated form whose parasite capacities are greatly reduced. The ultra high frequency circuit has, besides the components, at least one component fixing metallization and at least one microstrip formed by a metal track, on a first face of a dielectric substrate and, a ground plane metallization on a second face of the substrate. The ultra high frequency circuit is fixed to the base of a case. In order to reduce the parasite capacities formed between metallizations, the second metallized face of the substrate is locally demetallized, in line with the fixing metallization, and an air layer is introduced between the demetallized substrate and the base of the case.