Abstract: A signal processing method comprises: a) detecting sample auxiliary signals from an auxiliary signal and sample reference signals from a reference signal at different times; b) applying an auxiliary weight from a set of auxiliary weights to a corresponding sample auxiliary signal to create weighted sample auxiliary signals; c) applying a reference weight from a set of reference weights to a corresponding sample reference signal to create weighted sample reference signals; d) creating a summation value that represents the sum of the weighted sample auxiliary signals and the weighted sample reference signals; e) creating an error signal that represents the difference between the desired signal and the summation value; f) scaling the error signal to generate an update function; g) detecting the error signal; h) applying the update function to each of the auxiliary weights and reference weights; and i) returning to step (a).

Abstract: A method is disclosed for fabricating ohmic contacts on semiconducting diamond. A carbide forming metal is deposited over a surface of the semiconducting diamond. In some applications, one or more layers of an intermediate metal are deposited over the carbide forming metal. A corrosion resistant metal is then deposited over the intermediate metal, if present, or the carbide forming metal. The semiconducting diamond and metals are heated in an inert environment at a temperature anywhere from 350 to 1200 degrees Celsius.

Abstract: An apparatus and technique reduces the data transmission rate required to ansmit acoustic signals from undersea sensors to remote monitoring locations without degrading the surveillance information content of the signals. The signals are digitized and fed to an adaptive line enhancer (Wiener filter) which processes them so that a fast Fourier transform (Karhunen-Loeve approximation) coefficient generator can feed representative signals to a programmable quantizer and a signal averager. When significant shifts are detected in the fast Fourier transform coefficient variances, responsive signals are generated by the programmable quantizer for adaptive bit allocation. An interconnected multiplexer transmits multiplexed signals to the remote monitoring station where the inverse of the foregoing allows an analysis of the acoustic signals being monitored.

Abstract: A correlator which is capable of correlating two or more signals of unknown frequency and bandwidth receives inputs on each of two or more channels. For the case of a two-channel, or pairwise, correlator the two channels are designated a first channel and a second channel. For the pairwise correlator, a first adaptive linear predictive (ALP) filter filters the input signal from the first channel and a second ALP filter filters the input signal from the second channel, the two output signals of the filters being x(k) and y(k). The adaptive linear predictive filter is an adaptive time-domain digital filter which adapts its impulse response according to a certain algorithm. The filter output represents an adaptive linear predictive estimate of the current input value, based on many past inputs. The input signals to the two channels of the pairwise correlator may correspond to sensor outputs from two or more widely separated sensors.

Abstract: An adaptive detector comprises an adaptive linear prediction filter (ALPF) nd a detection processor.The adaptive filter comprises an input filter, adapted to receive an input signal x(k) and delay it by a time .DELTA.. An L-point, or L-tap, adaptive filter has an input connected to the output of the input filter, a signal r(k) appearing at the output of the filter. A means for summing has two inputs, one for receiving the signal x(k) and the other for receiving an inverted signal from the adaptive filter, the output of the summer being an error signal .epsilon.(k). A feedback amplifier, whose input is connected to the output of the summer, takes a portion 2.mu., of the output signal .epsilon.(k) and feeds it back to the adaptive filter, thereby modifying the tap weights of the adaptive filter.The detection processor comprises a circuit, whose input is connected to the output of the adaptive filter, to receive the signal r(k), for performing a K-point discrete Fourier transform (DFT) on the signal r(k).

Abstract: An input signal X(j) is fed directly to the positive port of a summing function and is simultaneously fed through a parallel channel in which it is delayed, and passed through an adaptive linear transversal filter, the output being then subtracted from the instantaneous input signal X(j). The difference, X(j)-Y(j), between these two signals is the error signal .epsilon.(j). .epsilon.(j) is multiplied by a gain .mu. and fed back to the adaptive filter to readjust the weights of the filter. The weights of the filter are readjusted until .epsilon.(j) is minimized according to the recursive algorithm: ##EQU1## where the arrow above a term indicates that the term is a signal vector. Thus, when the means square error is minimized, W.sub.(j+1) =W.sub.(j), and the filter is stabilized.

Abstract: A field effect transistor comprises a diamond substrate which has a p-type ion implanted region coterminous with a surface of the diamond substrate, wherein the ion implanted region has a hole concentration in the range of 1.times.10.sup.15 to 1.times.10.sup.17 holes/cm.sup.2, and a hole mobility equal to or greater than 1 cm.sup.2 /V-sec; spaced apart source and drain electrodes formed over the p-type ion implanted region on the surface of the diamond substrate; an electrically insulating material formed over the p-type ion implanted region on the surface of the diamond substrate between the source and drain electrodes; and a gate electrode formed on the surface of the insulating material.