Document Type and Number:
Japanese Patent JPS5156155
Kind Code:
A
Abstract:
A programmable analog transversal filter is disclosed for processing analog signals and comprising a charge-coupled device (CCD) for receiving a series of discrete analog signals to be delayed by increasing periods and applied to the outputs of the CCD, and a plurality of MNOS memory devices coupled to the taps of the CCD and being programmed so that the output of a CCD tap is multiplied by a particlar factor. In particular, the MNOS memory devices are disposed in a matrix of rows and columns. The outputs of the MNOS memory devices of each row are summed and the row output signal e(t- n eo(t) = SIGMA Wk . e(t-kT), k=1 WHERE Wk is the weighting factor associated with the Kth MNOS memory device are applied to corresponding inputs of a parallel-to-series converter taking the form of a CCD. The parallel-to-series converter then is enabled to serially read out the row outputs. The weighting factors are set into the system by varying the threshold voltage of the corresponding MNOS device. Positive and negative weighting factors are implemented by using first and second MNOS memory elements for each tap of the CCD, whereby depending upon the program incorporated into the system, one of the first and second MNOS memory devices is programmed to give a positive weighting factor and the other memory device a negative weighting factor. Further, a reiterative method of setting the weights into the MNOS device is used to compare the system output indicative of the weighting factor as set into one of the MNOS memory devices with the desired weighting factor as stored in a suitable storage memory such as a ROM, whereby a correction signal is developed to adjust the threshold voltage VTh of the one MNOS memory device in accordance with the stored weighting factor. In one illustrative embodiment, the weighting factors are set in accordance with sinusoidal signals, whereby the system performs a filtering function to provide an output upon receipt of an input signal of desired frequency. In addition, the MNOS devices are reprogrammable, thus permitting a single such system to be used in many different applications. In this regard, this system is particularly adapted for complex signal processing including filtering, generating desired functions, synthetic aperture radar signal processing and target identification processing.
Inventors:
JEIMUZU HAWAADO MIMUZU
Application Number:
JP11179575A
Publication Date:
May 17, 1976
Filing Date:
September 17, 1975
Export Citation:
Assignee:
WESTINGHOUSE ELECTRIC CORP
International Classes:
G06G7/16; G06G7/06; G06J1/00; G11C27/04; (IPC1-7): G06G7/16; G06J1/00