Charge transfer device transverse filter - has multiple electrode next to input stage, whose parts are allocated to filter outputs and coupled to them by charge transfer channels

摘要

The filter contains a charge transfer device (CTD), formed on a doped semiconductor substrate. The device has an input stage and several outputs coupled to a filter output. Partial signals which can be tapped at the outputs in parallel receive differing sign values. Next to the input stage is provided a multiple part electrode, whose partial electrodes are individually associated with the outputs and coupled to the same via independent CTD transmission channels. The input stage comprises a region, oppositely doped to the semiconductor substrate, a gate under biasing voltage, several transfer gate electrode, an input gate for the input signal and a second gate. One or several CTD transmission channels combine each a transfer electrode of a stage with all other transfer electrodes of an adjacent stage, in order to form a common electrode. Preferably the partial electrodes are of such surface ratio as to correspond to the valuation coefficients of the outputs.