Abstract: Weighting coefficients for a phased array antenna are iteratively refined to optimal values by a ‘bootstrapped’ process that starts with a coarse set of weighting coefficients, to which received signals are subjected, to produce a first set of signal estimates. These estimates and the received signals are iteratively processed a prescribed number of times to refine the weighting coefficients, such that the gain and/or nulls of antenna's directivity pattern will maximize the signal to noise ratio. Such improved functionality is particularly useful in association with the phased array antenna of a base station of a time division multiple access (TDMA) cellular communication system, where it is necessary to cancel interference from co-channel users located in cells adjacent to the cell containing a desired user and the base station.

Abstract: Weighting coefficients for a phased array antenna are iteratively refined to optimal values by a ‘bootstrapped’ process that starts with a coarse set of weighting coefficients, to which received signals are subjected, to produce a first set of signal estimates. These estimates and the received signals are iteratively processed a prescribed number of times to refine the weighting coefficients, such that the gain and/or nulls of antenna's directivity pattern will maximize the signal to noise ratio. Such improved functionality is particularly useful in association with the phased array antenna of a base station of a time division multiple access (TDMA) cellular communication system, where it is necessary to cancel interference from co-channel users located in cells adjacent to the cell containing a desired user and the base station.

Abstract: Weighting coefficients for a phased array antenna are iteratively refined to optimal values by a ‘bootstrapped’ process that starts with a coarse set of weighting coefficients, to which received signals are subjected, to produce a first set of signal estimates. These estimates and the received signals are iteratively processed a prescribed number of times to refine the weighting coefficients, such that the gain and/or nulls of antenna's directivity pattern will maximize the signal to noise ratio. Such improved functionality is particularly useful in association with the phased array antenna of a base station of a time division multiple access (TDMA) cellular communication system, where it is necessary to cancel interference from co-channel users located in cells adjacent to the cell containing a desired user and the base station.

Abstract: An accelerometer has a piezoelectric transducer which produces electrical signals in response to its deflection and comprises an elongated, continuous beam of generally flat configuration and narrow cross section to provide a bending axis which facilitates deflection of the free ends in response to shock in either or both of the linear and torsional modes. The beam is supported intermediate its ends by a mount, with the free ends of the beam preferably extending equidistantly in opposite directions from the mount so that the free ends of the beam deflect in the same direction in response to shock in the linear mode, e.g., along the X axis, and they deflect in opposite directions in response to shock in the torsional mode, i.e., about the Z axis.

Abstract: A device is disclosed for detecting the presence and direction of air flow through a passageway having a first opening and a second opening for air to flow therethrough in either a first direction or a second direction. The device comprises a piezoelectric sensor located within the passageway. A flow director is provided within the passageway for directing air flow through the passageway for impingement upon the sensor. The sensor generates a first electrical signal when air flows through the passageway in the first direction and a second electrical signal when air flows through the passageway in the second direction. A discriminator is electrically connected to the sensor for receiving the first and second electrical signals and for discriminating between the two signals to identify the direction of air flow through the passageway.

Abstract: A hail sensor is disclosed which contains a piezoelectric transducer positioned to produce an output signal when it is vibrated by a hailstone. In one embodiment, the transducer is mounted on a perforated member which is exposed to falling precipitation. In an alternative embodiment, the hailstone impacts a rebound surface and is deflected toward the transducer where an electrical output is produced.