Abstract: Grating lobe free scanning in a phased array with sparse element spacing is obtained by restricting the maximum scan angle for elements in the array, and arranging the elements in a convex form. One convex form is a paraboloid, which may be continuous, or piecewise in nature, tiled with flat segments.

Abstract: Grating lobe free scanning in a phased array with sparse element spacing is obtained by restricting the maximum scan angle for elements in the array, and cladding the array. Array elements may be integrated into the cladding.

Abstract: A microwave imaging system for constructing a stereoscopic microwave image of an object includes an antenna array with a plurality of programmable antenna elements and a processor. Each of the antenna elements is capable of being programmed with a respective first direction coefficient to capture a first microwave image of the object from a first focal point on the array. In addition, each of the antenna elements is capable of being programmed with a respective second direction coefficient to capture a second microwave image of the object from a second focal point on the array. The processor constructs the stereoscopic microwave image from the first and second microwave images.

Abstract: An antenna array for use within a microwave imaging system includes a plurality of reflecting antenna elements, each capable of being programmed with respective phase-shifts in a first pattern to direct a first beam of microwave radiation towards a first target, and each being capable of being programmed with respective phase-shifts in a second pattern to direct a second beam of microwave radiation towards a second target. To capture a microwave image of an object, the antenna elements are programmed with respective phase-shifts in an interleaved pattern including a portion of the first pattern and a portion of the second pattern.

Abstract: A microwave imaging system captures a microwave image of a target and minimizes noise in the microwave image using phase differentiation. A reflector antenna array is provided including a plurality of antenna elements for reflecting microwave radiation towards the target and for reflecting microwave radiation reflected from the target towards a microwave receiver. A processor programs the antenna elements with respective first phase shifts to capture a first microwave image of the target, and programs the antenna elements with respective second phase shifts to capture a second microwave image of the target. The first phase shift of each antenna element is 180 degrees different than the second phase shift for that antenna element. The processor minimizes noise from a combination of the first microwave image and the second microwave image.

Abstract: A microwave imaging system uses microwave radiation provided by a microwave source to image targets. The system includes an array of antenna elements that are capable of being programmed with a respective transmission coefficient to direct the microwave illumination from the microwave source toward a position on the target. The antenna elements are further capable of being programmed with a respective additional transmission coefficient to receive reflected microwave illumination reflected from the position on the target and direct the reflected microwave illumination towards a microwave receiver. A processor is operable to measure an intensity of the reflected microwave illumination to determine a value of a pixel within an image of the target. Multiple beams can be directed towards the target to obtain corresponding pixel values for use by the processor in constructing the image.

Abstract: A method to convert surplus nitroarene explosives into trinitrophloroglucinol and triaminotrinitrobenzene (TATB) is described. Picric acid is directly aminated to diaminopicric acid, which is converted to trinitrophloroglucinol and triaminotrinitrobenzene.

Abstract: A method to convert surplus nitroarene explosives (picric acid, ammonium picrate,) into TATB is described. The process comprises three major steps: conversion of picric acid/ammonium picrate into picramide; conversion of picramide to TATB through vicarious nucleophilic substitution (VNS) of hydrogen chemistry; and purification of TATB.

Abstract: An apparatus includes a polarization beam splitter, at least two reflectors and first and second polarization rotation devices. The polarization beam splitter and the at least two reflectors are arranged in a loop that is capable of propagating a clockwise signal component and a counterclockwise signal component. The first polarization rotation device is located in the loop between the polarization beam splitter and a first reflector of the at least two reflectors. The second polarization rotation device is located in the loop between the polarization beam splitter and an additional reflector of the at least two reflectors. The first polarization rotation device includes a serial arrangement of a reciprocal rotator and a nonreciprocal rotator.

Abstract: An apparatus includes a mixer, a combiner and first and second reflectors. The mixer has first and second inputs and has first and second outputs. The combiner includes first and second parts where the first output provides a mixed signal to the first part and the second part provides a combined signal to the second input. The first reflector receives a remaining signal from the first part and provides a reflected composite signal to the second part. The second reflector receives a split off pump signal from the first part and provides a reflected pump signal to the second part.

Abstract: An apparatus includes a mixer, a combiner and first and second reflectors. The mixer has first and second inputs and has first and second outputs. The combiner includes first and second parts where the first output provides a mixed signal to the first part and the second part provides a combined signal to the second input. The first reflector receives a remaining signal from the first part and provides a reflected composite signal to the second part. The second reflector receives a split off pump signal from the first part and provides a reflected pump signal to the second part.

Abstract: An apparatus includes a polarization beam splitter, at least two reflectors and first and second polarization rotation devices. The polarization beam splitter and the at least two reflectors are arranged in a loop that is capable of propagating a clockwise signal component and a counterclockwise signal component. The first polarization rotation device is located in the loop between the polarization beam splitter and a first reflector of the at least two reflectors. The second polarization rotation device is located in the loop between the polarization beam splitter and an additional reflector of the at least two reflectors. The first polarization rotation device includes a serial arrangement of a reciprocal rotator and a nonreciprocal rotator.

Abstract: An optical sampling method and apparatus use a probe pulse source of a predetermined optical wavelength range, e.g., 1560 nm, to sample incoming optical pulses in approximately the same wavelength range. The probe pulse source is frequency-doubled e.g., using a frequency doubler such as a nonlinear PPLN crystal, to obtain an intermediate second harmonic which may be filtered with a 780 nm bandpass filter to eliminate at least source frequency noise background. The filtered intermediate second harmonic is then mixed with the user input signal using an optional polarizing beam splitter and a dichroic beam splitter. The mixed signal is sent to a sum frequency generating (SFG) nonlinear crystal, e.g., a PPLN crystal, where the resulting frequency is near the third harmonic. The output from the SFG PPLN crystal may be filtered using a bandpass 515 nm filter to remove unwanted wavelengths and processed to measure/sense the near third harmonic content using a photomultiplier tube (PMT).

Abstract: Dinitropyrazolopyrazole-amine salts are used as burn modifier ingredients in gun propellant compositions.

Abstract: The present invention relates to new crystalline zeolite SSZ-50 prepared using a quaternary ammonium cation templating agent having the structure where X− is an anion which is not detrimental to the formation of the SSZ-50. SSZ-50 is useful in catalysts for hydrocarbon conversion reactions.

Abstract: The present invention relates to new crystalline zeolite SSZ-50 prepared using a quaternary ammonium cation templating agent having the structure 1

Abstract: The present invention relates to new crystalline zeolite SSZ-50 prepared using a quaternary ammonium cation templating agent having the structure 1

Abstract: The present invention relates to new crystalline zeolite SSZ-50 prepared using a quaternary ammonium cation templating agent having the structure 1

Abstract: The present invention relates to new crystalline zeolite SSZ-50 prepared using a quaternary ammonium cation templating agent having the structure where X- is an anion which is not detrimental to the formation of the SSZ-50. SSZ-50 is useful in catalysts for hydrocarbon conversion reactions.

Abstract: The present invention relates to new crystalline zeolite SSZ-47 prepared using a bicyclo ammonium cation templating agent.