Hughes Aircraft Company

Juri G Leetmaa

Richard V Basil, Jr

Charles F Montgomery

Donald G Swartz

Meredith K Eick

Neal C Silence

A dielectrically loaded waveguide switch is disclosed which provides high power handling capability, small size and low weight. The invention includes first and second dielectrically loaded waveguides selectively connected by a switch. In a specific embodiment of the invention, the switch includes a third dielectrically loaded waveguide mounted for communication with said first and second waveguides upon switch actuation.

Dielectrically loaded waveguide switch

A low noise coaxial microwave window of particular utility in hermetic and high power applications, having a metallic center conductor, a metallic outer support, and a ceramic support brazed between the two conductors. The brazed joints are specially prepared to have a series of layers and sublayers extending from the ceramic to the metal, as follows: ceramic, cermet, cermet-nickel alloy, copper-nickel alloy, copper, braze metal, and metallic piece. The nickel content of the cermet-nickel and copper-nickel alloys is limited so that the alloys are non-magnetic. The nickel-containing alloys assist in bonding the copper layer to the cermet in a reliable, reproducible fashion, but control of the nickel content avoids microwave intermodulation effects. Where the window separates a vacuum from another medium, the surface of the support contacting the vacuum is formed from at least two noncoplanar segments to eliminate the possibility of multipacting. The same techniques are used in waveguide microwave windows.

Microwave window

In a microwave resonator, a variable cavity-wall segmentation along the location of a propagational current null is employed for thermal-compensation purposes by utilizing it in conjunction with supplemental mechanisms which operate to counteract thermally-induced variations in the resonator's characteristic geometry. Because dimensional variations at a current null will have minimum impact on resonator coupling parameters, a variably-configured current-null segmentation serves in a minimal-impact fashion to absorb those thermally-induced dimensional variations which occur transverse to the null. Of the three specific mechanisms disclosed for variational counteraction in the typical context of a resonator having both longitudinal and transverse extent with respect to a propagational axis, the first is a thermally-invariant assembly which provides thermal stabilization by inhibiting variations in the resonator's characteristic longitudinal extent. The second is a thermally-responsive structure configured to provide thermal compensation by affirmatively introducing longitudinal variations which are inversely proportional to otherwise-uncompensated transverse variations. The third mechanism, which may be employed in conjunction with either of the other two and which may take the form of thermally-invariant inserts configured as part of the resonant cavity's longitudinal walls, provides a further degree of thermal stabilization by inhibiting thermally-induced variations in the resonator's characteristic transverse dimensions.

Thermally-compensated microwave resonator utilizing current-null

A method of eliminating a substantial portion of the nonlinear effects that occur in passive microwave devices operating under relatively high power conditions by use of small lightweight permanent magnets about the device structure while monitoring the level of such undesired signals.

Method of reducing spurious signal generation in passive microwave

A coupled-cavity microwave filter including a plurality of relatively high Q cylindrical cavity filters, a relatively large non-adjustable iris aperture coupling adjacent ones of the cavities, a relatively smaller secondary tuning aperture located near the edge of the irises separating the cavities, each such secondary tuning aperture containing a tuning screw extending through the wall of the cavity in order to provide adjustment of the coupling between such adjacent cavities without degrading the cavity Q.

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Los Angeles, CA, United States of America

Juri G Leetmaa