Finnegan, Henderson, Farabow, Garrett & Dunner
Input-weighted charge transfer transversal filter
 An input-weighted charge transfer transversal filter which comprises a charge transfer device including a plurality of stages, a plurality of signal charge injectors to inject into the stages of the charge transfer device weighted signal charge packets containing an AC component and a DC component, and a sense amplifier to sense the output signal of the transversal filter from the final stage of the charge transfer device, a DC charge injector to inject a predetermined quantity of DC charge into the first stage of the charge transfer device, and charge drains respectively coupled to the stages of the charge transfer device to drain at least DC charge from stages. Due to this arrangement the quantity of DC component injected by the signal charge injectors and transferred through the charge transfer device will be reduced. This leads to an improvement in packing density and signal detecting capability of the transversal filter. According to a first embodiment of this invention, positive weighting of a signal is achieved by injecting a weighted signal charge packet into the stage of the charge transfer device, while negative weighting is achieved by draining the weighted signal charge packet from the stage. According to a second embodiment, selection between positive and negative weighting depends on the polarity of an input signal applied to the signal charge injector. 
Tokyo Shibaura Denki Kabushiki Kaisha
H
H03H
inventional
Tetsuya Yasoji Tatsuo
Iida Suzuki Sakaue