Frequency dispersive transmitting array

A frequency dispersive beam forming apparatus for transmitting a radiation pattern of composite wave energy having the characteristics of a plurality of narrow-band beams, each of said narrow-band beams having a center frequency which is a function of a direction in which each of said narrow-band beams is propagated, comprising:

• a signal source having an output of broad-band signals in a selected band of frequencies;
• a transmitting array having a plurality of radiating elements;
• a plurality of time-delay devices, each of said time-delay devices having a delay time which is a multiple of the period of the dominant frequency radiated from a direction broadside to said array, each of said time-delay devices being coupled between successive ones of said plurality of said radiating elements;
• said array having a radiation pattern characterized by a plurality of main lobes and of sidelobes;
• said signal source being coupled to each of said radiating elements of said transmitting array through said time-delay devices by a feedline;
• and
• a plurality of window weighting function devices each of said window weighting devices being coupled between said signal source and one of said radiating elements by said feedline.

A method for propagating composite wave energy comprised of a plurality of components each having a frequency of wave motion which is a function of a direction (.theta.) in which each of said components is propagated, comprising the steps of:

• providing a transmitting array of radiating elements, said array having a radiation pattern;
• generating broad-band signals in a selected band of frequencies;
• feeding said broad-band signals be a feedline to each successive one of said plurality of said radiating elements through a time-delay device;
• delaying the emission of replicas os faid broad-band signals radiated by each successive one of said radiating elements by a delay time, said delay time being a multiple of the period of the dominant frequency radiated from a direction broadside to said array;
• and
• generating a window weighting function modifying said broad-band signals before emission, thereby controlling the behavior of said radiation pattern of said array.

A method of emulating a plurality of narrow-band beams radiated simultaneously in all directions from a broadside direction of a transmitting array each of said narrow-band beams having a center frequency corresponding to a direction in which each is emitted, comprising the steps of:

• providing a plurality of radiating elements arranged in an array, said array having a radiation pattern characterized by a main lobe and side lobes;
• providing broad-band signals to said array in a band of frequencies which will radiate said composite wave energy in all directions between an angle of -90.degree. and +90.degree. from a broadside direction to said array;
• providing a feedline to each of said radiating elements;
• providing a plurality of time-delay devices each of which is disposed in said feedline between successive ones of said plurality of said radiating elements, each of said time-delay devices having a delay time which is a multiple of the period of the dominant frequency radiated in a direction broadside to said array;
• and
• feeding said broad-band signals to each successive one of said radiating elements of said array through said time-delay devices so as to delay emission of said broad-band signals from each said successive one of said radiating elements.