Abstract: Semiconductor devices useful in high temperature sensing applications include a silicon carbide substrate, a silicon dioxide layer, and an outer layer of crystalline doped silicon carbide. The device is a 3C—SiC/SiO2/SiC structure. This structure can be employed to fabricate high temperature devices such as piezoresistive sensors, minority carrier devices and so on. The crystalline doped silicon carbide is dielectrically isolated from the substrate. The devices are formed by processes that include bonding a pattern wafer to a substrate wafer, selective oxidation and removal of undoped silicon, and conversion of doped silicon to crystalline silicon carbide. The level of doping and the crystalline structure of the silicon carbide can be selected according to desired properties for particular applications.

Abstract: A novel method for interconnecting leads in a high pressure transducer without the use of solder employs a ceramic disc containing a number of through holes. Each hole has a tube inserted therein, which tubes are connected to the disc by brazing or a high temperature attachment. Each tube protrudes from both sides of the ceramic. The ceramic is coated in appropriate areas with molymanganese film, which is over plated with gold. This overcoat forms a brazed compound surface attached to the tubes of the ceramic. A semiconductor pressure transducer has output leads which are inserted through the ceramic into each tube. The other side end of the tube receives high temperature wires from a suitable connecting device. Each tube is then crimped and spot-welded to hold both the lead from the transducer and the high temperature leads to produce a strong bond without the use of solder. The header itself it typically welded to a pressure point.

Abstract: An ultra miniature high temperature capacitive inductive pressure transducer is fabricated by MEMS techniques. The transducer consists of two separated pieces of silicon which form the plates of the capacitor, one of which plate is micromachined in such a way to allow a controlled deflection with pressure. The gap between the two capacitive plates is determined by an extending rim on one of the two plates. The two pieces of silicon are subsequently fusion bonded, leading a very small gap between the two plates. An inductor is formed on the top surface of one of the pieces of silicon by sputtering metal in a spiral like fashion on the back side of the non-micromachined plate.

Abstract: A radar antenna system comprises a wheel, cone or frustum having an axis. The wheel, cone or frustum has a circumferential portion adapted to engage at least one path disposed on a platform for revolving the radar array about the platform. A radar array is mounted on the wheel, cone or frustum, with the axis normal to a face of the radar array. The wheel, cone or frustum rotates about the platform as the radar array revolves around the platform during operation.

Abstract: The present invention relates to a compensated pressure transducer having a pressure transducer connected to a coarse temperature adjustment compensator and to a fine temperature adjustment compensator. The coarse temperature adjustment compensator includes an analog circuit and the fine temperature adjustment compensator includes a digital circuit. A pre-amplifier is connected between the pressure transducer and the fine temperature adjustment compensator.

Abstract: The present invention relates to a system for detecting aerodynamic instabilities in a jet turbine engine having a pressure transducer mounted in the engine. The pressure transducer, welded to a circuit in signal communication with a controller, is adapted to send measured pressure readings from air in a combustion chamber to the controller. The controller, located in spaced apart relation from the engine, is adapted by software to detect pressure patterns from the pressure signals generated by the transducer that are indicative of a stall or surge. A series of fuel and air valves located with compression and combustion chambers of the engine are in signal communication with the controller. The controller in response to detecting pressure signals indicating a stall or surge is operative to signals in the valves to change the air flow, air angle, fuel flow or speed to reduce the possibility of a stall or surge.

Abstract: A technique for suppressing interference with unknown phase shifts received by an array of sensor elements partitions the array into a plurality of subarrays. Each subarray is processed independently to suppress the interference. Next, the resulting data from each subarray are summed together. This summed data, which effectively represents data provided by the full array with interference suppressed, may be utilized to detect and/or localize a target of interest. Each subarray is processed independently of all other subarrays. No cross-subarray processing is required. This technique is applicable to linear arrays, multi-line arrays, planar arrays, cylindrical arrays, conformal arrays, and spherical arrays. Applicable sensors include acoustic sensors (e.g., sonar, ultrasonic), electromagnetic sensors (e.g. radar), and optical sensors (e.g., infrared, ultraviolet, visible light).

Abstract: A single chip multiple range pressure transducer device including a wafer having a plurality of simultaneously formed thinned regions. The thinned regions are separated by a fixed portion, and each have a same minimum thickness. The thinned regions have at least one different planar dimension. A plurality of piezoresistive circuits are formed on the wafer. Each of the circuits is associated with and at least partially formed above one of the thinned regions. The thinned regions deflect a different amount upon application of a common pressure thereto, whereby, when excited each of the circuits provides an output indicative the common pressure over a different operating range when the associated thinned region deflects.

Abstract: There is disclosed a weight reduction computer or a weight monitoring computer, which essentially enables a user to key in the foods consumed during the course of the day and to key in the activities participated in during the course of the day. Both the foods consumed and the activities participated in result in a caloric intake. The amount of calories consumed versus the amount of calories dissipated are automatically computed and an indication is provided to the user indicative of whether or not he is embarking on a successful weight reduction program. The amount of calories dissipated based on the user's exercise are accommodated according to the user's personal data, such as his weight, sex, age and so on. The user can also insert particular activities or foods in the computer, together with their amount of appropriate calories so that the computer can offer personalized data for the user.

Abstract: A portable security device for providing secure communications over a plurality of networks is presented. In one embodiment, the device comprises, at least one communication port for transfer of audio data, at least one communication port for transfer of digital data, a keypad, an encoding/decoding device, a conversion device operable to covert between audio and digital data and a processor, in communication with a memory, the keypad, the said encoding/decoding device, operable to execute code for selecting a configuration of a transmission and a reception port from among said communication ports dependent upon the presence of a network communication device and an input/output device in communication with said selected ports, providing data received from said selected reception port to said encryption/decryption device for encrypting; and providing said encrypted data to said selected transmission port.

Abstract: In accordance with a first aspect, a method for operating an electronic device adapted to be electronically coupled to at least one microprocessor based device and prevent unauthorized access to data exchanged between the at least one microprocessor based device and other microprocessor based devices, the method including: in a first mode, establishing a secure point-to-point communications session with another like device and receiving security data from the other like device, the security data being associated with an intended recipient microprocessor based device; and, in a second mode, receiving the data from an originating one of the at least one microprocessor based devices, encrypting the data using at least the received security data and sending the encrypted data to the originating microprocessor based device.

Abstract: There is described an accelerometer which is fabricated utilizing a beam diaphragm sensor employing dielectrically isolated resonant beams. Each resonant beam is subject to an acceleration. One beam is an acceleration sensing beam and contains a mass which is coupled to the deflecting diaphragm. As the accelerometer is subjected to acceleration, the acceleration sensing beam will alter its resonant frequency according to the applied acceleration, while the other beam is immune to acceleration and therefore, provides a relatively fixed resonant frequency. One then takes the difference frequency between the two beams to obtain an output frequency signal which is relatively independent of temperature and/or biasing changes.

Abstract: An improved method of estimating target elevation angle for dual squinted beam radar systems is disclosed. The target's elevation angle is estimated by receiving complex I/Q data from two receive radar beams and calculating the complex ratio of the complex I/Q data. The calculated complex ratio is compared to a set of previously determined reference complex ratios in complex lookup tables that have been corelated to known target elevation angles.