Ultra high frequency circuit with low parasite capacities
AssigneeThomson-CSF
InventorsAlain Bert, Serge Malbe
Life of this patent
Estimating the term…
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.
Claims7
An ultra high frequency circuit with low parasitic capacitance, comprising:
- a dielectric material substrate;
- at least one metallization on a first face of said substrate for fixing a component of the ultra high frequency circuit;
- a ground plane metallization on a second face of said substrate;
- a case having a metal base which supports said ground plane;
- a microstrip type connection line being formed by a microstrip on said first face and said ground plane metallization;
- one local dematallization of said ground plane in a region opposite said fixing metallization;
- an air layer in said region between said substrate and said base having a thickness of at least 100 microns;
- wherein the parasitic capacitance between the metallizations on said first and second faces of said substrate is reduced by said local demetallization.
Dependencies are inferred from the claim text.