Raytheon Company

Lockheed Sanders, Inc.

Sanders Associates Limited

Miles E Goff

David E Meharry

Jun-ichi Sano

Raymond S Pengelly

Systems and methods are presented for employing arrays of coupling strips to measure misalignment of layers of multilayer devices as a function of directional coupling between pairs of strips. Each array is capable of detecting misalignment only in the direction perpendicular to the axes of the coupling strips, although multiple arrays may be employed for measuring misalignment in more than one direction. Such arrays are easily manufactured onto existing multilayer devices, and may be excised from such devices after misalignment has been measured.

Coupler array to measure conductor layer misalignment

A microstrip to circular waveguide transition having an elongated circular waveguide portion and a stripline circuit portion disposed within the waveguide portion. The stripline includes a strip conductor disposed in a strip conductor plane. The strip conductor extends along a longitudinal axis of the circular waveguide portion from a first region of the transition to a longitudinally spaced second region of the transition. The stripline circuit portion includes a pair of overlying ground planes extending along the longitudinal axis from the first region to the second region, such pair of ground planes being disposed in overlying planes parallel to the strip conductor plane. The strip conductor is spaced from a pair of diametrically opposed first portions of the sidewalls in the first region and bends towards a first of a pair of diametrically opposed second portions of the sidewalls and away from a second one of the pair of opposed second portions of the sidewalls as such strip conductor extends within the waveguide portion towards the second region. The pair of overlying ground planes is disposed adjacent the diametrically opposed sidewall portions of the sidewalls in the first region of the transition and bend away from the first one of the pair of diametrically opposed second portions of the sidewalls and towards the second one of the diametrically opposed second portions of the sidewalls as such pair of ground planes extends within the waveguide section towards the second region. With such an arrangement, the stripline circuit portion provides two symmetrically located ground planes, which make two symmetrical E, field vectors. X-axis components of these vectors add to excite the desired mode in the circular waveguide. Y-axis components of these two vectors are in opposite directions, and will thus cancel out the contribution of coupling to the undesired orthogonal mode in the circular waveguide. This cancellation, due to symmetry, is not related to any particular wavelength, and thus the phenomenon is very broadband.

Microstrip to circular waveguide transition with a stripline portion

A balun transformer and inductor are proposed having geometries that provide several windings of conductors in small areas. In one embodiment, the windings of the balun transformer and inductor have octagonal shapes with a lower and upper layer of wound conductors. The upper layer lies on supporting posts that stand on pedestals. The lower layer of conductors shadow the upper layer while curving to avoid the pedestals.

MMIC airbridge balun transformer

An amplifier having an uncompensated gain which decreases with increasing temperature. The amplifier includes an integrated circuit chip having formed thereon a plurality of serially coupled amplifier stages. Each one of a portion of such stages has temperature compensation circuitry. Such circuitry includes a plurality of selectable gains, such gain being selected in accordance with temperature of the chip. The stage has a higher gain at a temperature above a predetermined threshold level associated with such stage and a lower gain at temperature below such predetermined threshold level associated with such stage. Each one of such stages is associated with a different predetermined threshold level. Each one of the stages includes a gain stage having a switchable feedback element, such stage providing a first gain when such element is switched into one state and a second gain when such element is switched into a second state. The temperature compensation circuitry switches such element into one of the states selectively in accordance with the temperature of the chip. Each one of the stages includes a gain stage having: a feedback element; and a switch, such element being in shunt with the switch. The switch is operable to either shunt such element or un-shunt such element. The stage provides a first gain when such element is shunted by the switch and a second gain when such element is un-shunted by such switch. The temperature compensation circuitry places such switch is a condition to either shunt such element or un-shunt such element selectively in accordance with the temperature of the chip.

Temperature compensated amplifier and operating method

A mixer circuit is provided which incorporates inductive elements for low voltage applications. The circuit consists of a balanced amplifier and a switch composed of transistor pairs driven by a local oscillator signal for multiplying the signal to produce a circuit output signal having a predetermined intermediate frequency. Inductors are used to provide degenerative feedback in the balanced amplifier portion of the circuit. The inductors generate negligible noise and produce a negligible dc voltage drop. The transistors in the circuit are thereby maintained in saturation regions of operation as desired. In accordance with another aspect of the invention, an inductor or, alternatively, a parallel inductor-capacitor circuit, is used as a constant current source in conjunction with the input transistors in the balanced amplifier portion of the circuit.

Low noise mixer circuit having passive inductor elements

A monolithic integrated circuit power sensor provides a monolithic integrated circuit substrate a conversion element formed either on or in the substrate for converting microwave energy into heat, an electrically insulating dielectric layer affixed to the conversion element, and an integrated circuit, heat sensitive element formed in sufficiently close proximity to the conversion element to be thermally coupled thereto through the dielectric layer for sensing temperature changes in the conversion element.

Monolithic microwave power sensor

A monolithic microwave integrated circuit device provides a microwave transmission line with a resistor coupled thereto and a heating element thermally coupled to the resistor but electrically insulated therefrom by a dielectric layer. Heating the resistor with the heating element causes either a change in resistance of the resistor or the generation of noise by the resistor. Either the resistor or the heating element is constructed using monolithic integrated circuit construction techniques on the same circuit substrate with the transmission line.

Monolithic microwave integrated circuit noise generator and variable

A successive detection logarithmic amplifier consists of multiple stages, with each stage containing a field-effect transistor (FET) which functions as both an amplifier and a detector. The FET, having an external gate biasing terminal, is biased to operate in its linear region as an amplifier. The gate-source junction of the FET, which is a diode, functions as the detector. When a signal exceeding a predetermined threshold is applied to the FET, the gate-source junction conducts current in the forward direction during the positive half-cycles of the input signal. During the negative half-cycles of the input signal, very little current flows through the gate-source diode junction. The time average of the forward current peaks produces a voltage across a resistor connected between the external gate bias terminal and ground. The voltages at the external gate bias terminals of each of the stages are summed to form a video output signal, a piece-wise linear voltage which is a logarithmically proportional to the input signal at the initial stage.

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Carlisle, MA, United States of America

Miles E Goff