Abstract: There is disclosed a combined absolute differential pressure transducer which consists of two sensors made from the same wafer silicon and selected to be adjacent to each other on the wafer. Since the same pressure is applied to the boss side of both sensors and a second pressure is applied to the opposite side of the differential sensor, deflection and the stress of the second sensor is determined by the pressure difference across the deflecting portion of the sensor. To obtain the same stresses in the thin section of each sensor, the overall active area of each sensor is different. For the same thickness read, the absolute value of P2?P1 where P2 is the pressure applied to the front side of the two sensors and P1 is the pressure applied to the differential sensor through the metal tube is less than P2 to obtain the same stress in each sensor a great active area in the differential sensor is required.

Abstract: An azimuth drive for a radar array comprises at least one circular track mounted to a wheel on which the radar array is mounted. A motor is coupled to the at least one circular track and capable of moving along the track in the tangential direction, to relocate the center of mass of the wheel on which the radar array is mounted.

Abstract: A stop member is secured to a piezoresistive semiconductor bossed diaphragm at the peripheral area, and includes a first and second slotted apertures in communication with the central active area, the first and second slotted apertures correspond in location with opposing sides of a central boss. The stop member includes a stop cavity located between the first slotted aperture and the second slotted aperture, and the stop cavity overlies the central boss and is separated therefrom to enable the diaphragm to deflect when a force is applied and to enable the central boss to impinge on the surface of the stop cavity when an excessive force is applied. The first and second slotted apertures permit another force to be applied to the active region of the diaphragm in a direction opposite to the stopped direction. A second stop member is secured to the diaphragm to provide stopping in either direction.

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: A solid state fuel cell is fabricated from three substructures. There is a porous anode made from n+ silicon which is surrounded by a non-porous ring. The pore size of the anode material is sufficiently large to allow hydrogen gas to flow through and is of a sufficiently high conductivity to easily permit current flow of electrons. One side of the anode has enlarged pores and a layer of titanium and platinum is sputtered or otherwise deposited on the surface with the enlarged pores to produce a coated surface. A cathode is made in a similar manner and is fabricated as the anode. There is a center electrolytic section made from a low conductivity silicon or silicon carbide. The center electrolytic section has the coated side of the anode secured to one side and has the coated side of the cathode secured to the other side. The other or un-coated face of both the anode and the cathode has an electrical contact secured thereto to permit electrons to leave the anode and to reenter the cathode.

Abstract: A monopulse radar system generates elevation and azimuth difference monopulse estimates of the location of targets in each range cell, where the target may be either a single or plural target, each of which is made up of multiple scattering sources. Each azimuth-elevation estimate is based on a transmitted pulse or burst at a given frequency, different from other frequencies in a set of pulses or bursts. A test statistic is generated for each set. The statistic relates to the shape in an azimuth-elevation plane of the cluster of estimates. The test statistic is compared with a threshold to decide whether a single target or plural targets exist in the range cell.

Abstract: A protective cover or grid for an ultrasound transducer comprises a series of vertically spaced members separated from one another by a pre-determined distance, each member being of substantially uniform width and arranged in a cylindrical shape. The protection grid includes a cavity for receiving a cylindrical transducer. The protection grid operates as both a physical protection mechanism for protecting the cylindrical transducer housed therein as well as operating as an impedance matching device.