General Electric Company

Martin Marietta Corporation

Michael J Fithian

David R Helms

Mark R Lang

Mooshi R Namordi

A low power consumption amplifier that is essentially insensitive to the process used to fabricate the active devices of the amplifier employs feedback to minimize variations in electrical characteristics of the devices. For weight-sensitive microwave applications, a high electron mobility transistor (HEMT) or a pseudomorphic high electron mobility transistor (PHEMT) may be selected as an active device for each stage of the amplifier. HEMTs and PHEMTs typically exhibit greater device gain than do MESFETs, especially at the upper portion of X-band and above, so that a HEMT- or PHEMT-based stage of an amplifier where additional overall gain is required, can be achieved without significantly adversely affecting power consumption demands, and attendant electrical energy storage/generation requirements while achieving and/or maintaining an overall flat gain characteristic of the amplifier.

Low power consumption process-insensitive feedback amplifier

A microwave phase shifter has a plurality of sequentially arranged, independently-actuatable sectiions, the total phase shift is the sum of all of the sections. The phase shifter has a common substrate, supporting several switching elements, with at least one switching element being assigned to each phase section; the switching elements are fastened to the common substrate with the element connections are all substantially in a first plane above the substrate. A first layer of a dielectric material is affixed adjacent to the first plane. Phase shift elements, such as microstriplines of a known length or inductive patterns of conductor, imparting the desired section phase shift, are fabricated upon a surface of the first dielectric layer furthest from the substrate, and are interconnected to and from the sections, or onto or off of the phase shifter at this level. Connections between the phase-shift elements and the switching element connection pads are by conductive pathways in this plane, with conductive vias formed through the intervening dielectric material. An additional dielectric layer is placed over the phase element conductive patterns, both for element protection and to support either control wiring, which can be routed as required in another surface plane and connected down to the control connection pads using other via connections, and/or for supporting a ground plane helping to define microstripline phase-shift elements.

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Liverpool, NY, United States of America

Michael J Fithian