Microwave ground shield structure

Claim 1

In a microwave circuit of a three plate construction having a plurality of independent circuits formed in an inner level, said inner level being sandwiched between two dielectric boards with conductive layers on their outer surfaces to provide a pair of outer grounded layers, the improvement comprising: a plurality of through holes formed in said dielectric boards between the physically neighboring circuits in said plurality of independent circuits in said inner level and extending from one of said outer conductive layers to the other, said through holes being formed in line and connected to a common electrically conductive layer at intermediate portions thereof, said through holes being formed at offset positions on the opposite sides of the common electrically conductive layer, and a metallized coating on the inner surfaces of said through holes connecting said outer conductive grounded layers and providing a ground shield between said neighboring circuits.