Patent ID: 8477075

Claim:
An antenna for broadband satellite communication comprising an array of primary horn antenna elements which are connected to one another by a waveguide feed network, wherein the array includes a number N=N 1 ×N 2 of primary horn antenna elements where N 1 >4 N 2 , N 1 and N 2 are even integers, the total aperture area A of the antenna is A=L×H, where L≧4 H and L<N 1 λ, where λ is the minimum free-space wavelength of the electromagnetic wave to be transmitted or to be received, the primary horn antenna elements allow the reception and the transmission of two orthogonal linear-polarized electromagnetic waves in that they have a rectangular aperture area a=l×h where l<h and l<λ, and each have an approximately square output, where L=N 1 l, H=N 2 h and A=N 1 ×N 2 ×l×h=L×H, and the primary horn antenna elements are fed directly at their output via rectangular waveguides such that one of the orthogonal linear polarizations is supplied and carried away parallel to the aperture area, and the other of the orthogonal linear polarizations is supplied and carried away via a waveguide septum on a plane at right angles to the aperture area, the horns of the primary horn antenna elements are compressed and have a length l H <1.5λ at right angles to the aperture area, and wherein the waveguide feed network comprises a first feed network for one of the two orthogonal linear polarizations and a second feed network, for the other of the two orthogonal linear polarizations, each of the two feed networks is in the form of a binary tree with binary E- and H-power dividers, such that the respective last power divider on the lowest level of the binary tree combines the powers of two half-apertures, in each case with N/2 primary horn antenna elements, for each of the two orthogonal polarizations, separately and symmetrically, the aperture configuration of the antenna in each case approximately follows the relationship: p 1,j <p 2,j <p 3,j < . . . <p k,j =p k+1,j =p k+2,j = . . . =p k+m,j >p k+m+1,j >p k+m+2,j >p k+m+3,j > . . . >p 2k+m,j where k and m are integers and 2k+m=N 1 , and the powers p i,j , i=1 . . . N 1 , j=1 . . . N 2 , denote the power contributions of the individual primary horn antenna elements, the aperture configuration is implemented by symmetrical and asymmetric binary E- and H-power dividers in each of the two feed networks for each of the two orthogonal polarizations, and the entire aperture area is covered by a phase equalization grid, where the meshes of the phase equalization grid have a square dimension with an edge length b, and in each case, approximately, b=l, h=2 b and b<λ, such that, in the direction N 1 , the webs of the grid lie above the abutting edge of two adjacent horn antenna elements and, in the direction N 2 , the webs of the grid are each located approximately precisely at the center of the aperture area of the individual horn antenna elements.