In general, in accordance with an exemplary aspect of the present invention, a low-loss interface for connecting an integrated circuit such as a monolithic microwave integrated circuit to an energy transmission device such as a waveguide is disclosed. In one exemplary embodiment, the interface comprises a pin attached to a matching network that matches the impedance of the energy produced at the circuit to the impedance required by the waveguide without the use of a dielectric material.

Low-loss interface

In general, in accordance with an exemplary aspect of the present invention, a low-loss interface for connecting an integrated circuit such as a monolithic microwave integrated circuit to an energy transmission device such as a waveguide is disclosed. The interface comprises an isolation wall placed between an input and output region of an integrated circuit to reduce ripple and isolate the waveguide cavity from the monolithic microwave integrated circuit circuitry. The interface further comprises a turning screw or other similar member that is configured to closely match the impedance of integrated circuit 11 with the impedance at interface 10 to further reduce loss.

Adjustable low-loss interface

An apparatus for mounting a waveguide window or conduction member into a housing such that a smooth gradient of the coefficient of thermal expansion exists between the housing and the window or conduction member, thereby reducing the internal stress which results from ambient temperature variations. The apparatus comprises a frame member for mounting a feedthrough member into a housing. The frame member includes a buffer section having a plurality of sections, each section having a material which progressively varies the coefficient of thermal expansion. The frame member further includes additional stress relief features and structural elements facilitating manufacture and assembly of the apparatus.

Low stress waveguide window/feedthrough assembly

A miniature coaxial connector with a mating end for mating to another connector and a termination end for direct connection to a circuit, provides a closely controlled impedance along its entire length. The connector comprises a coax assembly (14, FIG. 2) having a glass bead (120), a conductive pin (28) projecting through the bead, and a conductive impedance member (40) surrounding the bead. The coax assembly is installed in a connector body (12) having a hollow front mating end portion (50) and a rear end portion (52). The impedance member of the coax assembly has a flange (46) lying on the front face (34) of the bead, and the rear of the body includes a precision passage (60) with the pin projecting completely through the passage and with only air between the pin and passage walls. This arrangement provides precision alignment of the pin with grounded conductive surfaces surrounding it. The flange provides a precision transformer at the front of the pin where it will engage a socket of a mating connector.

RF feed-through connector

A durable, broad-band low insertion loss RF feedthrough is formed of a straight conductor (5) centrally supported by, hermetically sealed to and axially extending through the center of a strong, rigid, impervious ceramic disk (3). The ceramic disk is hermetically sealed, directly or indirectly, to the metal barrier (11) through which the feedthrough is to propagate RF energy. The new ferrule and ferrule-less ceramic metal RF feedthroughs avoid the use of glass, conventional in existing feedthroughs. The novel feedthrough serves as the principal element of a microwave microstrip line to waveguide transition.

Millimeter wave ceramic-metal feedthroughs

A hybrid package in which Kovar feedthroughs are friction welded to an aluminum housing. Friction welding produces a very strong weld joint which resists the thermal stresses induced between the aluminum housing and Kovar feedthroughs by the large difference in their coefficients of thermal expansion. Friction welding also produces a very small heat affected zone, while brazing, soldering and other types of welding produce large heat affected zones which can cause annealing problems. The aluminum package is easy to machine, light in weight and provides good heat dissipation for the hybrid microcircuits in the package.

Marijan D. Grgas

Papers

Hermetically sealed aluminum package for hybrid microcircuits