| 摘要 |
<p>Antenna system with a double coverage area for microwave radar imaging by satellite moving in low orbit. Two main reflectors (1,2) are provided, associated with two primary arrays (3,4) which are fed alternately from a single amplification chain. Switching between the two primary arrays may be achieved by two orthogonal-polarisation accesses, onto which two waves with different polarisations can be sent. According to a specific embodiment, electronic polarisation switches (13) alternately switch over the microwave signal (10) to one or the other accesses of dual-polarisation horns which constitute the active array (5). The alternately polarized wave (9) which is transmitted therefrom is reflected by an auxiliary reflector (18) to at least one collector array (19), connected to the two primary arrays (3, 4). According to another embodiment, the two primary arrays (3,4) are each connected to a respective collector array (51,55). Electronic polarisation switches (13,14) alternately switch over the microwave signal (10) to one or other of the two active arrays (5,66). The selectively polarized wave (9,53) which is transmitted therefrom is reflected by a respective auxiliary reflector (17, 18) towards the respective collector (51,55), each wave (9,53) having a different polarisation. Each collector (51,55) is linked to the corresponding primary array (3,4) by a short connector (32,56). <IMAGE></p> |
