Trw Limited

Northrop Grumman Systems Corporation

Paul S Lee

Barry Ross Allen

Chung-Wen Dennis Lo

Gee Samuel Dow

Eric W Lin

Jay S Pearlman

John Joseph Berenz

Steven S Chan

Mikio L Yujiri

Pei-Ming Daniel Chow

Steven W Fornaca

Karen E Yokoyama

Bill H Quon

Thomas K Samec

John D O'Keefe

Wayne W Lam

Barry H Stark

Chungcytz Liu

A compact inline waveguide power divider is provided that comprises a primary waveguide in communication with two parallel waveguides. The two parallel waveguides are stacked on top of one another and each parallel waveguide further comprises an output port. Accordingly, an input signal is transmitted through the primary waveguide and split between the two parallel waveguides. A resistive slot is formed in each of the parallel waveguides, thereby increasing output port isolation through dissipation of reflected power from one output port to the other. Further, a stepped or tapered impedance transformation is applied in each parallel waveguide to provide wide band frequency matching. Alternately, the primary waveguide and the parallel waveguides may be configured as a waveguide power combiner rather than a divider, wherein the parallel waveguides comprise input ports and the primary waveguide comprises an output port.

Waveguide power divider and combiner utilizing a resistive slot

A direct detection receiver for a passive microwave and millimeter wave radiometric imaging system. The receiver includes a balanced switch low-noise amplifier (BSLNA). A front-end, low-noise amplifier (LNA) is inserted before the BSLNA to achieve a low-noise figure, as well as provide sufficient gain to minimize the input noise figure degradation due to loss of the BSLNA. A high-electron mobility transistor (HEMT) diode is used as a power detector. The front-end amplifier, BSLNA and diode are process compatible for monolithic integration.

Monolithic, low-noise, synchronous direct detection receiver for passive

A method of calibrating gains and offsets for a two-dimensional detector array 10 comprising individual detector elements 14, including: (a) focusing a first incoming image signal at a first power level onto the detector array 10; (b) reading the corresponding electrical signals from the detector elements 14 as a first image frame at the first power level; (c) for each detector element 14, translating the first incoming image signal by a detector element distance onto an adjacent detector element; (d) reading the corresponding electrical signal from the detector elements 14 as a second image frame at the first power level; (e) focusing a second incoming image signal at a second power level onto the detector array 10; (f) reading the corresponding electrical signals from the detector elements 14 as a first image frame at the second power level; (g) for each detector element 14, translating the second incoming image signal by a detector element distance onto an adjacent detector element; (h) reading the corresponding electrical signals from the detector elements 14 as a second image frame at the second power level; (i) selecting a reference detector element 18; (j) determining the gain of detector elements adjacent to the reference detector element 18; and (k) determining the offset of the adjacent detector elements 14.

Focal plane array calibration method

An anti-reflection coating for optical elements and a method for forming an anti-reflection coating on an optical element includes one or more layers of a woven plastic mesh material that may be layered on the surface of an optical element such as the lens and secured thereto with a suitable adhesiveor pressed on to the surface by either a peripheral retaining ring or bodily pressed in place by a low loss, low dielectric medium. The number and thickness of the layers of the woven plastic mesh material are selected to provide optimal reduction of reflection losses.

Anti-reflection treatment for optical elements

A focal plane imaging array (FPIA) (16) for use in a direct detection imaging device (10) for conducting radiometric imaging at microwave and millimeter-wave frequencies is disclosed as having an internal electronic calibration source (36). The plurality of energy detecting pixel elements (14) which comprise the FPIA (16) include a detection circuit (34) and a calibration circuit (36). The calibration circuit (36) is uni-directionally coupled to the detection circuit (34) to allow a known calibration signal 'pulse' to be introduced into the detection circuit (34). The calibration pulse is processed by the pixel detection circuit and the output signal is compared with the pixel's responsivity value. Adjustments in the pixel gain and sensitivity may then be made as appropriate.

Focal plane imaging array with internal calibration source

A microwave locating system is provided for locating known features and distinguishing between different types of features. The locating system includes a plurality of modulated microwave power sources located on known features and radiating modulated microwave signals having modulated frequencies selected in accordance with the known features. A video detection sensor camera is located remote from the sources for sensing microwave signals within a field of view and providing location signals for each of the sources. The camera includes an array of receiver elements which provide narrow bandwidth filtering so as to identify received signals as one of a plurality of selected modulated frequencies. The locating system further provides an image of the location signals which distinguishes between different selected located features.

Microwave aircraft landing system using narrow bandwidth filtering

A microwave image scanning apparatus which utilizes a dispersive waveguide wedge in front of a microwave sensor. Similar to an optical prism, the waveguide wedge resolves multi-spectral microwave energy from various directions into the same direction for detection by the microwave sensor and subsequent formation of a refined high quality video image. The waveguide wedge consists of a collection of waveguide channels having their longitudinal axes aligned substantially in parallel.

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La Palma, CA, United States of America

Paul S Lee