The Marconi Company Limited

Gec-marconi Limited

Bae Sysytems Plc

Robert Brian Greed

John R Wallington

Ramanlal Chhiba Mistry

Keith Ronald Rosenthal

A circuit board is provided, and a method for manufacturing the same, suitable for use in high frequency circuits, and comprising a planar pattern of transmission line conductors for linking components formed on or within the circuit board, the transmission line conductors being formed within a corresponding pattern of trenches arranged so that the conductors lie beneath a finished surface of the circuit board which is polished flat to permit one or more cover boards to be bonded thereto.

Circuit board defined by transmission line patterns disposed within trenches and covered by a conformal layer

A number of electronic modules,are mounted on a cold finger,disposed within a sealed housing,the interior,of which is evacuated. To minimize heat transfer by conduction, gaps are provided in the dielectric substrates carrying the input and output transmission lines providing signal paths between the modules and electrical connectors on the exterior sidewalls 106, 108 of the housing. The gaps are bridged by thin conductive wires, thereby providing low electrical, but high thermal, impedance at the gaps. A number of module assemblies may be stacked on a single cold finger. To allow modules to be adjusted under actual operating conditions, a cover having a number of spring-loaded screwdrivers extending through vacuum tight seals and aligned with adjustable components of the modules, may be temporarily substituted for the enclosure lid,The springs urge the screwdrivers out of engagement when no adjustment is being made to minimize heat transfer.

Cryogenic electronic assembly

An improved microwave switch incorporating a fin line structure is described. Microwave switches incorporating fin line structures enable microwave energy to be passed to a load or reflected back to the source, by controlling the conductance state of diodes mounted on the fin line structure. The present invention enables the electrical performance of such switches to be greatly improved. The height of a waveguide channel in the vicinity of the fin line structure is very greatly reduced thereby forcing a waveguide mode of propagation into a slot line so that the fin line structure receives substantially all of the energy supplied to the switch. Higher order modes which are generated at the fin line structure are attenuated by lossy material positioned in choke cavities mounted on either side of the fin line structure.

Microwave switch

A versatile switch for routing very high frequency signals is formed in microstrip. Each switch has four ports, and a number of switches can be interconnected to provide complex routing or power splitting functions.

Growing community of inventors

Colchester, United Kingdom

Robert Brian Greed