Charge transfer device transversal filters
AssigneeInternational Business Machines Corporation
InventorsLawrence Griffith Heller, James Merrill White
Life of this patent
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Abstract
A charge transfer device transversal filter is provided including two equivalent charge transfer device shift registers for translating with respect to each other, a first analog signal referred to as an input signal and a second analog signal, referred to as a transfer function signal, with respect to each other. The discrete analog signals are temporarily added on field effect transistor gates. The non-linear characteristics of the field effect transistor performs multiplication. The field effect transistor currents are then summed to complete the filter convolution. The disclosed invention is implemented in either charge-coupled-device technology or bucket-brigade technology.
Claims10
A charge transfer device transversal filter structure comprising a first charge transfer shift register responsive to a first sampled analog signal,
- a second charge transfer shift register responsive to a second sampled analog signal,
- said first and second shift registers including
- a plurality of stages through which said sampled analog signals are discretely shifted to provide relative translation between said first and second sampled analog signals,
- a plurality of multiplication means connected to corresponding pairs of stages from said first and second shift registers for producing a signal proportional to the square of the additions of the discrete analog signal samples in said corresponding shift register stages for each shifting operation,
- and summing means connected to said plurality of multiplication means for summing signals proportional to the squares of the additions of said discrete analog signal samples for each shifting operation to produce a resultant output signal proportional to the addition of the squares of the additions of said translated analog signal samples wherein said resultant output signal is a convolution or correlation function of said first and second analog signals.
Dependencies are inferred from the claim text.