Transversal filter

A transversal filter comprising:

• a doped semiconductor substrate;
• an analog charge transfer device multistage shift register integrated on said substrate and including a transfer channel, a plurality of inputs and an output, each of said stages including a plurality of shift electrodes for receiving respective repetitive shift pulses;
• and
• a plurality of evaluation circuits assigned to said shift register inputs and each including
• a zone common to all evaluation circuits and doped opposite to the doping of said substrate,
• a respective electrical terminal for said oppositely doped zone for receiving first pulse voltages at a pulse repetition rate higher than the shift pulse repetition rate,
• a first input gate and a second input gate, one of said input gates connected to receive an input signal and the other input gate connected to receive a constant DC voltage, and
• a transfer gate directly adjacent said transfer channel and an electrical terminal connected thereto for receiving second voltage pulses,
• at least one of said evaluation circuits including an additional zone doped opposite to said substrate and an electrical terminal connected thereto for receiving additional first pulses which are phase-displaced with respect to said first pulses.

A transversal filter comprising:

• a doped semiconductor substrate;
• an analog charge transfer device multistage shift register integrated on said substrate and including a transfer channel, a plurality of inputs and an output, each of said stages including a plurality of shift electrodes for receiving respective repetitive shift pulses;
• and
• a plurality of evaluation circuits assigned to said inputs, each evaluation circuit of at least one pair of said evaluation circuits located on a side of a stage of said shift register opposite the other evaluation circit of the pair, each of said evaluation circuits including
• a zone doped in opposition to said substrate, p1 a common first electrical terminal connected to said doped zones of said pair of evaluation circuits and a respective first electrical terminal connected to the other doped zones for receiving first pulse voltages at a pulse repetition rate higher than the shift pulse repetition rate,
• a first input gate and a second input gate,
• a common second electrical terminal connected to one of said input gates of said pair of evaluation circuits and respective second electrical terminals connected to one input gates of the remaining evaluation circuits for receiving an input signal,
• a common third electrical terminal connected to the other input gates of said pair of evaluation circuits and respective third electrical terminals connected to the other input gates of the remaining evaluation circuits for receiving a constant DC voltage,
• a transfer gate directly adjacent said transfer channel,
• a common fourth electrical terminal connected to said transfer gates of said pair of evaluation circuits and a respective fourth electrical terminal connected to said transfer gates of the remaining evaluation circuit for receiving second voltage pulses.

A transversal filter comprising:

• a doped semiconductor substrate;
• an analog charge transfer device multistage shift register integrated on said substrate and including a transfer channel, a plurality of inputs and an output, each of said stages including a plurality of shift electrodes for receiving respective repetitive shift pulses;
• a plurality of evaluation circuits assigned to said shift register inputs and each including
• a zone doped opposite to said substrate and an electrical terminal connected to said zone for receiving first pulse voltages at a pulse repetition rate higher than the shift pulse repetition rate,
• a first input gate electrode and a second gate electrode, one of said input gate electrodes connected to receive an input signal and the other input gate electrode connected to receive a constant DC voltage, and
• a transfer gate electrode directly adjacent said transfer channel and an electrical terminal connected to said transfer gate electrode for receiving second voltage pulses;
• and
• an insulating layer on said substrate and supporting said transfer gate electrodes, said insulating layer, for each stage of said shift register, including first portions supporting said transfer electrodes adjacent a first predetermined number of said shift electrodes and second, thicker portions supporting said transfer electrodes adjacent a second predetermined number of said shift electrodes and determining the input signal weighting of said evaluation circuits.