Adapting circular shading to a truncated array of square elements

Claim 2

A shaded transducer system comprising: an annular baffle a symmetrical array of uniform equispaced square transducer elements truncated to fit onto said annular baffle: a multiplicity of shading resistances, each of said resistances providing a coefficient of radiation value; an electronic assembly having means to energize said elements of said array and having at least transmitter capability; connecting means connecting each of said elements to said electronic assembly through at least one of said multiplicity of shading resistances; and said elements, said resistances, said coefficient of radiation values, and said electronic assembly so correlated that said array will produce a radiation pattern which is equivalent to the radiation pattern which would be produced by a concentric stack of decreasing radii circular transducer elements, with the largest radius circular element positioned adjacent said annular baffle.

Claim 3

A transducer system as set forth in claim 1 wherein: said concentric stack of circular transducer elements includes a circular element of smallest diameter which has a radius which encloses as completely as possible the most central of said square transducer elements and has the same area as the area of the most central of said square transducer elements, and a circular element of largest diameter which has a radius which encloses as completely as possible all of said square transducer elements which lie along the row and the column of said square transducer elements which include said most central of said square transducer elements.

Claim 4

A transducer system as set forth in claim 2 wherein: said concentric stack of circular transducer elements have radii of about 0.564(x), 1.58(x), 2.55(x), 3.54(x), and 4.53(x), where (x) is a dimension of said square element, from the smallest circular element to the largest circular element, respectively; and have annular shading coefficient of radiation values of 0.132(x) for the smallest circular element and about 0.274(x), 0.301(x), 0.195(x), and 0.0984(x) respectively for the remaining circular elements whereby said array produces a first side lobe level lower than -45 dB.

Claim 5

A shaded transducer system comprising: an annular baffle a symmetrical array of uniform equispaced square transducer elements truncated to fit onto said annular baffle; a multiplicity of shading resistances, each of said resistances providing a coefficient of radiation value; an electronic assembly having means to detect signals from said elements of said array and having at least receiver capability; connecting means connecting each of said elements to said electronic assembly through at least one of said multiplicity of shading resistances; and said elements, said resistances, said coefficient of radiation values, and said electronic assembly so correlated that said array will produce a receiving pattern which is equivalent to the receiving pattern which would be produced by a concentric stack of decreasing radii circular transducer elements, with the largest radius circular element positioned adjacent said annular baffle.

Claim 6

A shaded transducer system comprising: an annular baffle a symmetrical array of uniform equispaced square transducer elements truncated to fit onto said annular baffle; a multiplicity of shading resistances, each of said resistances providing a coefficient of radiation value; an electronic assembly having means to detect signals from said elements of said array and having at least receiver capability; connecting means connecting each of said elements to said electronic assembly through at least one of said multiplicity of shading resistances; and said elements, said resistances, said coefficient of radiation values, and said electronic assembly so correlated that said array will produce a receiving pattern which is equivalent to the receiving pattern which would be produced by a concentric stack of decreasing radii circular transducer elements, with the largest radius circular element positioned adjacent said annular baffle.

Claim 7

A transducer system as set forth in claim 4 wherein: said concentric stack of circular transducer elements includes a circular element of smallest diameter which has a radius which encloses as completely as possible the most central of said square transducer elements and has the same area as the area of the most central of said square transducer elements, and a cIrcular element of largest diameter which has a radius which encloses as completely as possible all of said square transducer elements which lie along the row and the column of said square transducer elements which include said most central of said square transducer elements.

Claim 8

A transducer system as set forth in claim 5 wherein: said concentric stack of circular transducer elements have radii of about 0.564(x), 1.58(x), 2.55(x), 3.54(x), and 4.53(x), where (x) is a dimension of said square element from the smallest circular element to the largest circular element, respectively; and have annular shading coefficient of radiation values of 0.132(x) for the smallest circular element and about 0.274(x), 0.301(x), 0.195(x), and 0.0984(x) respectively for the remaining circular elements whereby said array produces a first side lobe level lower than -45 dB.