摘要 |
The present invention relates to filters, and is more particularly concerned with apodising filters. As shown, a spatial discriminator 100 comprises an antenna array 102 consisting a plurality of antenna elements 102a, 102b, 102c, 102d, 102e, 102f, 102g, 102h. The antenna array 102 is a phased antenna array and each antenna element 102a, 102b, 102c, 102d, 102e, 102f, 102g, 102h has a fixed phase difference relative to each other antenna element. The antenna array 102 is connected to an array 104 of apodising filters. Each antenna element 102a, 102b, 102c, 102d, 102e, 102f, 102g, 102h is connected to a respective apodising filter element 104a, 104b, 104c, 104d, 104e, 104f, 104g, 104h. The apodising may be carried out in the microwave domain or, alternatively, in the optical domain if the signals from the antenna array are converted from electrical signals to optical signals. Advantageously, if the apodising is carried out in the optical domain, commercial off the shelf components can be used in the array 104 of apodising filters.
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