Bae Systems Information and Electronic Systems Integration Inc.

Sanders Associates Limited

Lockheed Sanders, Inc.

Bae Systems Information and Electronics Systems Integration Inc.

Gradual Tech Software L.l.c.

David E Meharry

David P Charette

Miles E Goff

Randall R Lapierre

Bernard J Schmanski

Stephen A Hedges

Scott D Powell

A miniaturized multi-sectioned, directional coupler using a multi-layer MMIC process, the coupler comprising, a monolithic microwave integrated circuit, having a central section with a relatively tight coupling, surrounded by sections of lighter coupling, the relatively tight coupling being comprised of a pair of spiral coupled lines, and the lighter coupling being comprised of meandered edge couple lines with capacitive loading of the lines in several places.

Miniaturized multi-section directional coupler using multi-layer MMIC process

A MMIC amplifier is directly connected to the balanced feed points at the aperture of an antenna to eliminate the distance between electronics coupled to the antenna and the antenna itself, such that interfaces, components and connection lines which introduce losses and parasitic effects that degrade system performance are eliminated due the direct connection. Expanding the aperture of the antenna to accommodate the direct connection of a MMIC amplifier to balanced feed points of an antenna has been found to have no deleterious effects on antenna performance. Moreover, when coupling the MMIC amplifier to an unbalanced coaxial line, any associated ripple is minimized due to the direct connection.

Method for direct connection of MMIC amplifiers to balanced antenna aperture

The replacement and elimination of duplexers in a tightly coupled dipole phased array starts with transmit and receive functions physically separated and having different antenna port feeds. The simple coupling network used with tightly coupled dipole arrays is replaced by a state switch which alternates between a coupling state and a dipole feed connection state. The basic method can be applied to antenna apertures of various kinds, including both linear and dual polarized versions. The ability to locate state switches at various nodes in tightly coupled dipole phased arrays permits flexibility in antenna design and eliminates bulky and lossy components, simplifies the design requirements and allows independent optimization of the components.

Method and apparatus for elimination of duplexers in transmit/receive phased array antennas

A wide bandwidth planar four port MMIC transformer is provided by input diplexers which divide up the incoming signal into a high band and a low band, with the resulting signals coupled to high band and low band four port transformers implemented in one embodiment using spiral inductors and coupled lines, the outputs of which are combined using two output diplexers to provide a decade bandwidth transformer.

Decade bandwidth planar MMIC four port transformer

A wide bandwidth microwave balun utilizes frequency band splitting and two conventional baluns operating in a high frequency band and a low frequency band, which when combined offer a full bandwidth output, thus to offer wide bandwidth impedance matching and second-harmonic rejection.

Wide bandwidth microwave balun

A differential amplifier is formed from a first single-ended amplifier circuit, a second single-ended amplifier circuit, and a four-port transformer circuit coupled to the first and second single-ended amplifier circuits to form the differential amplifier.

Wideband differential amplifier including single-ended amplifiers coupled to a four-port transformer

An enhanced duplexer () which includes a combination of high dynamic range (HDR) amplifiers () and a naovel signal cancellation circuit topology (). Return signals from the circulator () are fed into the first HDR amplifier (). A portion of the transmit signal is sampled with a directional coupler () and amplified with a second HDR amplifier () and then combined with the output of the first HDR amplifier () using a second directional coupler (). The gain and phase of the second io amplifier () are adjusted so the leakage signals are canceled () to enable a radar system to simultaneously transmit and receive signals to and from an antenna with increased sensitivity of operation.

Duplexer for simultaneous transmit and receive radar systems

Widebrand differential amplifier including single-ended amplifiers coupled to a four-port transformer

A monolithic microwave switch matrix includes fully monolithic construction for crossovers as well as switches and input transmission lines configured as lumped equivalent transmission lines for reduced power loss. The crossovers include a grounded conductor located between the crossing transmission lines.

Monolithic microwave airbridge

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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Lexington, MA, United States of America

David E Meharry