The diagonalisation BFN for satellite reflector antennas with simultaneous overlapped multiple coverages

The author presents a synthesis method to determine the best electrical performance that can be achieved by an established array-fed reflector antenna configuration with a lossless BFN. By the hardware implementation of the mathematical diagonalisation technique, the network enabling the generation of any set of orthogonal output voltages with the minimum number of network components is found. During the synthesis process, the parameters of the diagonalisation BFN (DBFN), that exhibits one output port for each feed, are adjusted to explore the best achievable performance in terms of EOC directivity values. On the basis of these reference values, the method allows the definition of the optimum BFN, having a reduced number of output ports but still maintaining the DBFN architecture. The topology of this new network does not exhibit any crossing of the signal paths, thus becoming quite attractive. Comparisons between different synthesis techniques are also presented for a typical three coverage scenario