Analog transversal filtering and correlation with progressive summation of analog signals

A system for performing the function:

• ##EQU5## where e.sub.out (t) is the output voltage to be produced as the said function of an analog input signal e.sub.in (t) as a function of time (t), e(t-k.tau.) represents the k.sup.th sample thereof at successive time intervals .tau., and W.sub.k represents multiplicative weighting constants for the respective samples k, where k= 0, 1, . . . (N-1), comprising:
• a charge transfer device having N successive stages 0, 1, 2 . . . (N-1) and means for shifting charge packets through said successive stages at a cyclic shift rate corresponding to a charge propagation time .tau. in each said stage thereof,
• (N) charge injector means respectively associated with said (N) stages of said charge transfer device, each thereof for injecting a charge packet into the respectively associated stage,
• (N) weighting means of weights W.sub.0, W.sub.1, . . . W.sub.(N.sub.-1) connected to respectively associated ones of said (N) charge injector means,
• means for sampling an input signal e.sub.in (t) at successive intervals .tau., in timed relation to said cyclic shifting of said charge transfer device, said sampling means providing said input signal samples to said weighting means in parallel, and said charge injector means receiving the corresponding, weighted outputs of said respectively associated weighting means for injecting corresponding charge packets into the respectively associated stages of said charge transfer device, timed in relation to said cyclic shift rate thereof,
• each said stage of said charge transfer device substantially simultaneously receiving a propagating packet from a preceding stage and a charge packet injected by the injector means respectively associated therewith and summing the said propagating and injected charge packets for subsequent propagation thereof as a summation charge packet to a next succeeding stage of said charge transfer device whereby the summation charge packet in the last successive stage corresponds to the output signal e.sub.out (t) in accordance with the aforesaid function, and
• means for sensing a potential induced by each said summation charge packet in said last, successive stage of said charge transfer device, thereby to provide said output signal e.sub.out (t).

A method of progressive summation of analog signals through use of a charge transfer device having a plurality of successive stages and means for shifting charge packets through said plurality of successive stages at a predetermined cyclic shift rate, and a plurality of charge injecting means respectively associated with at least selected ones of said plurality of successive stages, each said charge injecting means injecting a charge packet into a respectively corresponding one of said plurality of successive stages of said charge transfer device, and a plurality of signal processing means respectively associated with said plurality of injecting means, comprising:

• sampling an input analog signal in time sequence with said cyclic shift rate of charge packets through said stages of said charge transfer device,
• processing each said analog signal sample in parallel processing functions,
• supplying the parallel processed signal samples to respectively associated charge injector means for injecting charge packets corresponding to said respective, parallel processed signal samples into respectively associates stages of said charge transfer device for simultaneously summing said injected charge packet with a charge packet shifted thereinto from a preceding stage of said charge transfer device to produce a summation charge packet,
• shifting the summation charge packet to the successive stages of said charge transfer device, and
• sensing a potential induced by each said summation charge packet from the last of said successive stages of said charge transfer device and producing a corresponding summation signal output sample corresponding thereto.