Rockwell International Corporation

Derek T Cheung

Harold R Fetterman

Cecil L Hayes

Gabor C Temes

Joseph T Longo

A Mike Andrews, Ii

A millimeter wave power generator combines two laser beams, tuning the beat frequency to the desired millimeter wave value with an opposing pair of millimeter wave cavities. The combined beam is diffracted onto a plurality of externally powered, modulation doped field effect photodetectors (MDFEPs). A plurality of antennas is provided, one between each pair of adjoining MDFEPs. The antennas are parallel, and each is driven by the MDFEPs at its ends. The back propagating millimeter wave radiation is reflected forward by a wire grid parallel to the antennas. The grid is situated between the diffractor and the MDFEPs, and is spatially tuned to constructively interfere the reflected back propagating with the forward propagating millimeter wave radiation.

Millimeter wave power generator

A thermal detector array includes a substrate layer with a pyroelectric layer attached to the substrate, a plurality of detector regions being defined in the pyroelectric layer by openings through the layer. An array of cavities in the substrate surface separates the detector regions from the surface. First and second electrodes are placed on opposite sides of each detector region or on a single side in a coplanar embodiment. The array is joined to a signal processing device by means of corresponding metallic contacts on the pyroelectric layer and the processing device.

Pyroelectric thermal detector array

In this monolithic detector array, a signal processing layer is epitaxially formed directly on an active detector layer. The active detector layer is supported by a transparent substrate. The three layers are made of intrinsic semiconductors of the same conductivity type (e.g., n-type). The semiconductor forming the active layer has a smaller bandgap than the signal processing and substrate layers. A plurality of vias of opposite conductivity type (e.g, p-type) extend through the signal processing layer into the active detector layer where they form p-n junctions with the active detector layer. These p-n junctions collect charges generated by the radiation and the vias conduct these charges to the signal processing layer where gates, AC background suppression circuitry, and a charge coupled device process the photogenerated signals.

Self-multiplexed monolithic intrinsic infrared detector

A plurality of metal deposits are formed on the insulated surface of a semiconductive material to create an array of capacitive photodetectors. A plurality of metal columns connect the metal deposit of each photodetector to a corresponding metal deposit on the insulated surface of a silicon charge-coupled device (CCD). In this manner, the voltage signal generated in each photodetector is capacitively coupled to the charge-coupled device. The metal deposit on the CCD forms a gate for a fill/spill circuit which provides the input to the charge-coupled device. In a preferred embodiment, a bi-polar fill/spill circuit is used to provide an input to the CCD which is proportional to the change in voltage of a photodetector during a predetermined clocking period.

Capacitively coupled array of photodetectors

An improved input circuit is provided for an array of photo detectors. For each photo detector in the array, the circuit utilizes a first FET with a source for coupling to an output of a photo detector, a gate coupled to a first gate voltage, and a drain for coupling to an output circuit. The first gate voltage is provided by a feedback circuit which utilizes matched properties of adjacent FETs. In one embodiment, FETs are used in an open loop feedback circuit to reduce the input impedance seen by the photodiode at the source of the first FET. A similar objective is accomplished in another embodiment utilizing FETs in a closed loop feedback circuit. Further embodiments utilize FETs arranged as a differential amplifier with active loads to provide a low input impedance and a virtual ground at the source of the first FET.

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Thousand Oaks, CA, United States of America

Derek T Cheung