Patent ID: 7129888
Filing Date: 2006-10-31
Classification: G01S,Y10S

Abstract:
1. A sidelobe canceler, comprising: first transducing means forming a beam for preferentially receiving main signals from a particular direction, and also forming sidelobes by which unwanted signals may be received from directions other than said particular direction; an integer number, which integer number may be equal to unity, of auxiliary transducing means, located adjacent to said first transducing means, each of said auxiliary transducing means being for receiving ancillary signals from said particular direction and from said other directions; controllable weighting means coupled to each of said auxiliary transducing means, for weighting said ancillary signals received therefrom in accordance with weight signals applied to each of said weighting means, to form weighted auxiliary signals; summing means coupled to said first transducing means and to said weighting means, for subtracting from said main signals the sum of said weighted auxiliary signals, to thereby form said main signals with reduced levels of said unwanted signals; and weight establishing means coupled to said first transducing means and to said auxiliary transducing means, and to said controllable weighting means, said weight establishing means further comprising: (a1) a plurality of sets of correlators, each of said sets of correlators including a plurality of first input ports, one of which is coupled to each of said main and auxiliary transducing means for receiving said main and auxiliary signals, each of said sets of correlators also including a second input port, the number of said sets of correlators being equal to the number of said transducing means, and said second input port of each of said sets of correlators being coupled to a different one of said transducing means, each of said sets of correlators including a plurality of subsets of correlators, the number of said subsets of correlators in each of said sets of correlators being equal to the number of said first input ports of said set of correlators, each of said subsets of correlators being coupled to one of said first input ports of the associated set of correlators, and all of said subsets of correlators of each of said sets of correlators being coupled to said second input port of the associated set of correlators by way of complex conjugating means, whereby each of said correlators operates on the complex conjugate of the transduced signal applied to said second input port of the associated set of correlators, each of said subsets of correlators also including a cascade of a plurality of delay means, the number of which delay means in each cascade is one less than the number of said weight signals applied to the corresponding one of said controllable weighting means, which number of delay means may be equal to zero, each of said cascades of said plurality of delay means having an input end coupled to receive transduced signals from one of said first input ports of the associated one of said sets of correlators, each of said cascades of said plurality of delay means having associated therewith one tap for each of said delay means except for the first delay means of each subset, which has associated therewith two taps, each of said taps of any one of said subsets of delay means producing identical signals, mutually delayed from each other; (a2) a plurality of summing multipliers associated with each of said subsets of correlators, equal in number to the number of said weight signals applied to the associated one of said controllable weighting means, each of said summing multiplier means including a first input port coupled to one of said taps associated with the associated one of said cascades of delay means for receiving cascade signal therefrom, and a second input port coupled by way of said complex conjugate means to said second input port of the associated one of said sets of correlators for receiving complex conjugate signal therefrom, for producing correlation coefficients representing the correlation of said complex conjugate signal applied to said second input port of said summing multiplier means with said cascade signal applied to said first input port of said summing multiplier means; b. a plurality of first processing means, each of said first processing means including first and second input ports and an output port, for forming at said output port an intermediate weighting coefficient representing the quotient of a signal applied to said first input port divided by a signal applied to said second input port; c. a plurality of second processing means, each of said second processing means including first, second and third input ports, and first and second output ports, for producing at said first output port a signal representing the product of the signal applied to said first input port multiplied by the conjugate of the signal applied to said second input port, and for producing at said second output port a signal representing a difference, wherein said difference is the difference between the signal applied to said third input port and a second product, wherein said second product is the product of three factors, which are (i) the signal applied to said first input port, (ii) the signal applied to said second input port, and (iii) the conjugate of the signal applied to said second input port; d. a plurality of third processing means, each of said third processing means including first, second and third input ports, and an output port, for producing at said output port a signal representing a difference, wherein said difference is the difference between the signal applied to said third input port and a third product, wherein said third product is the product of the signal applied to said first input port multiplied by the signal applied to said second input port; e. coupling means coupled to said correlators and to said first, second and third processing means for arranging said processing means in groups defined by ranks, each of which is associated with at least one of said sets of correlators, each of said ranks of processing means being coupled for receiving correlation coefficients from at least one of said sets of correlators, and also being coupled for receiving intermediate weighting coefficients produced by all higher rank of processors, if any, within the highest rank, coupling one of said correlation coefficients from one of said sets of correlators, in common, to said second input port of said first processing means, and coupling said correlation coefficients from one of said sets of correlators to said first input port of said first processing means, thereby producing at said output port of said first processing means the highest rank of intermediate weighting coefficients, and within each rank of said processing means except said highest rank, coupling rows of processors in at least first rows, and last and intermediate rows, if present, where a single processor in a rank containing only one row is deemed to be in both first and last rows of its rank, said coupling means, within each rank except said highest rank, coupling said first input port of said second processing means of said first row to said second output port of said second processing means of said last row of the next higher rank, said second input port of said second processing means of said first row to receive said intermediate weighting signal from the next higher rank, said third input port of said second processing means of said first row to receive one of said correlation coefficients from one of said sets of correlators, said first output port of said second processing means of said first row in common to said first input ports of said third processing means of said first row, said second output port of said second processing means of said first row to one of (i) said third input port of a second processing means of the next row within said rank and (ii) in common to said second input ports of said first processing means of said rank, said second input port of said third processing means of said first row to receive said intermediate weighting signal from said next higher rank, said third input port of said third processing means of said first row to receive said correlation coefficient from a correlator of said set of correlators, said output port of said third processing means of said first row to one of (i) said third input port of a third processing means of the next row within said rank and (ii) to said first input port of said first processing means of said rank, said first input port of said second processing means of said last row to receive said correlation coefficient from a correlator of one of said sets of correlators, said second input port of said second processing means of said last row to receive said intermediate weighting signal from said output port of a first processing means of said highest rank, said third input port of said second processing means of said last row to one of (i) said second output port of a second processing means on a previous row and (ii) said output port of a first processing means of the next higher rank, said first output port of said second processing means of said last row in common to said first input port of said third processing means of said last row, said second output port of said second processing means of said last row in common to said second input ports of said first processing means of said rank, said second input port of said third processing means of said last row to receive said intermediate weighting signal from said output port of one of said first processing means of said highest rank, said third input port of said third processing means of said last row to one of (i) said output port of said third processing means of the previous row and (ii) and to receive a correlation coefficient from one of said sets of correlators, said coupling means further coupling, within a rank, said first input port of said second processing means of one of said intermediate rows to said second output port of said second processing means of said last row of a higher rank, said second input port of said second processing means of one of said intermediate rows to receive said intermediate weighting coefficient from said output port of said first processing means of a higher rank, said third input port of said second processing means of an intermediate row to said second output port of said second processing means of the previous row, said first output port of said second processing means of an intermediate row in common to at least one of said first input ports of said third processing means of the same intermediate row, said second output port of said second processing means of an intermediate row to said third input port of said second processing means of the next row, said second input port of said third processing means of an intermediate row to receive said intermediate weighting coefficient from said output port of one of said first processing means of a higher rank, said third input port of said third processing means of an intermediate row to said output port of said third processing means of the previous row, and said output port of said third processing means of an intermediate row to said third input port of said third processing means of the next row; and f. means for processing said intermediate weighting signals for generating weight signals, and for applying said weight signals to said weighting means.