Abstract: A thermally stabilized cascode heterojunction bipolar transistor (TSC-HB) having the current and power generation regions in separate temperature zones, each transistor collector in a cold zone connected directly and individually to an emitter terminal of a corresponding transistor in a hot zone, thereby limiting the current available to the emitter of the transistor in the hot zone. Such an interconnection of transistors prevents the transistor in the hot zone from drawing more current from other transistor sources when increases in temperature occur. This achieves thermal stability and prevents the transistors from overheating and burning out.
Type:
Grant
Filed:
June 6, 1997
Date of Patent:
March 4, 2003
Assignee:
The United States of America as represented by the Secretary
of the Navy
Abstract: A light beam encoded with data simultaneously reads out data stored in tracks on an optical disk and produces a reflected beam directed to a detector array. The data stored on the optical disk and the encoded data may be components of vector arrays. As the light beam illuminates the rotating optical disk, the data stored on the disk is multiplied by the encoded data. The products of the multiplication are encoded in the reflected beam. A multiplicity of data is read out in parallel from the optical disk and simultaneously correlated with the encoded data. This comparison or correlation operation is performed on digitally encoded data utilizing convolution, or with analog encoding. The present invention can be utilized in pattern matching.
Type:
Grant
Filed:
January 19, 2001
Date of Patent:
December 31, 2002
Assignee:
The United States of America as represented by the Secretary
of the Navy
Inventors:
John N. Lee, Ray B. Brown, Jr., Robert L. Denningham
Abstract: An improved optic flow sensor is provided which affords enhanced bandwidth without the use of a lens. A plurality of photoreceptor circuits, arranged in a linear array, sense light received from a visual field and produce a plurality of photoreceptor signals in accordance with the light sensed. A negative iris, disposed between the visual field and the photoreceptor circuits, blocks a portion of the light from the visual field so that the light blocked by the negative iris is not received by the photoreceptor circuits. The photoreceptor signals are used in determining optic flow in the visual field. The invention is useful for implementation using micro electromechanical system (MEMS) techniques.
Type:
Grant
Filed:
September 28, 2001
Date of Patent:
December 10, 2002
Assignee:
The United States of America as represented by the Secretary
of the Navy
Abstract: The optical image reject down converter maps a received radio frequency (RF) into an arbitrary intermediate frequency range and precludes interference between the received signals. A received radio frequency signal is downconverted into an intermediate frequency band for use by an electronic circuit in other devices. Optical light is divided, in a first path light is transferred into an optical sideband by a first optical modulator or phase modulator. Light in a second path is converted into 18 GHz sidebands. The signal is amplified and additional sidebands are generated by a received 9 GHz signal. The filtered sideband is heterodyned with the 25 GHz signal of path one, resulting in downconversion to 2 GHZ. Image frequencies which are present in the optical link are filtered and are rejected.
Type:
Grant
Filed:
August 9, 2000
Date of Patent:
November 26, 2002
Assignee:
The United States of America as represented by the Secretary
of the Navy
Abstract: A digital envelope detector (consisting of both hardware and software) that provides accurate measurements of changes of peak values of an AC signal (these peak values constitute the envelope of a signal). Such accurate envelope measurements are required, e.g., to optimize the accuracy and selectivity of chemical sensors. The envelope values required for these sensors can not be obtained with common instruments (e.g. voltmeters) since these meters require that successive peaks be the same amplitude. Therefore, they can not measure the envelope of a gradually increasing or decreasing AC signal from the chemical sensors. The only possible alternative to this invention is high speed, high resolution analog-to-digital conversion (ADC) followed by extensive statistical analysis. The ADC method is much more expensive, slower, and excessively complicated compared to the invention.
Type:
Grant
Filed:
June 28, 2000
Date of Patent:
October 8, 2002
Assignee:
The United States of America as represented by the Secretary
of the Navy
Abstract: This invention is a traction splint including a tension applying mechanism with an outer knob to apply tension to a tension stirrup through belting wound about a shaft while such tension is released by turning of an inner knob in the opposite direction. Both of these knobs are uni-directional relative to rotative movement but in opposite directions. A folding support leg and relatively simple and yet extremely efficient bindings and appendage supports are also included features.
Abstract: This invention is a vending system for floral type products and includes a plurality of product containing cubicles with an access door operatively associated with each. A controllable locking structure is used with each door and is connected to a validator for accepting and totaling money. Selectors are provided for choosing the appropriate cubicle door to be opened and these selectors are resettable to a different amount of money by simply resetting a dial on the exterior backside of the panel.