116 results about "Instantaneous bandwidth" patented technology

Reconfiguration of parasitically controlled elements in a phased array is used to expand the range of operational functions. Embedded array elements can be frequency tuned, and bandwidth can be improved by using reconfiguration to broaden the bandwidth of the embedded elements. For high gain arrays, beam squint can be a limiting factor on instantaneous bandwidth. Reconfiguration can alleviate this problem by providing control of the element phase centers. Scan coverage can be improved and scan blindness alleviated by controlling the embedded antenna patterns of the elements as well as by providing control of the active impedance as the beam is scanned. Applying limited phase control to the elements themselves can alleviate some of the complexity of the feed manifold. A presently preferred method of designing reconfigurable antennas is to selectively place controlled parasitic elements in the aperture of each of the antenna elements in the phased array. The parasitic elements can be controlled to change the operational characteristics of the antenna element. The parasitic elements are controlled by either switching load values in and out that are connected to the parasitic elements or are controlled by applying control voltages to variable reactance circuits containing devices such as varactors. The parasitic elements can be controlled by the use of a feedback control subsystem that is part of the antenna system which adjusts the RF properties of the parasitic components based on some observed metric. The controllable characteristics include directivity control, tuning, instantaneous bandwidth, and RCS.

The present invention provides an advanced adaptive predistortion linearization technique to dramatically reduce nonlinear distortion in power amplifiers over a very wide instantaneous bandwidth (up to 2 GHz) and over a wide range of amplifier types, input frequencies, signal types, amplitudes, temperature, and other environmental and signal conditions. In an embodiment of the invention, the predistortion linearization circuitry comprises (1) a higher-order polynomial model of an amplifier's gain and phase characteristics—higher than a third-order polynomial model; (2) an adaptive calibration technique; and (3) a heuristic calibration technique. The higher-order polynomial model is generated by introducing, for example, a plurality of multi-tone test signals with varying center frequency and spacing into the power amplifier. From the power amplifier's corresponding output, the nonlinearities are modeled by employing a higher-order curve fit to capture the irregularities in the nonlinear transfer function. Different distortion transfer functions can be implemented for different operating conditions. The adaptive calibration technique is based on a feedback analysis technique, which updates the applicable distortion transfer function by analyzing the error signal between the introduced input signal and the output signal in real-time. The heuristic calibration technique implements different distortion transfer functions based on historical operating conditions and optimal configurations of the power amplifier.

A method for predicting pore pressure is described which initially involves obtaining, for one point in a volume of Earth, a value of pore pressure and one or more seismic attributes. A relationship is determined between the value of pore pressure and the seismic attribute, for example by use of a neural network. Seismic data is then obtained for the volume of earth and the same attributes as selected above when determining relationship are extracted from the seismic data for another point in the volume. The extracted seismic attributes are then used as inputs to the previously determined relationship to produce as an output, a prediction of pore pressure at the other point. The seismic attributes are frequency related seismic attributes and include for example instantaneous frequency, weighted mean frequency, instantaneous pseudo-quality factor, instantaneous dominant frequency, instantaneous bandwidth, instantaneous phase, effective bandwidth, peak frequency, envelope and energy half time.

The present invention provides a high-performance adaptive digital receiver with adaptive background control that optimizes the performance in rapidly changing signal environments and provides 3.6 GH; instantaneous bandwidth, SFDR>90 dB, SNR=66 dB, with dynamic digital channelization. The receiver takes advantage of several levels of adaptivity that conventional approaches do not offer. In addition to a dynamic digital channelizer that is adaptively tuned based on detected signals, the present invention employs a powerful software reconfigurable digitizer that is adaptively optimized for the current signal environment to control important receiver parameters such as bandwidth, dynamic range, resolution, and sensitivity.

A system determines bandwidth use by queues in a network device. To do this, the system determines an instantaneous amount of bandwidth used by each of the queues and an average amount of bandwidth used by each of the queues. The system then identifies bandwidth use by each of the queues based on the instantaneous bandwidth used and the average bandwidth used by each of the queues.