| 摘要 |
An antenna excitor (2) for two different frequency bands comprises two polarising diplexers (3,4) into each of which two mutually perpendicular linearly polarised electromagnetic waves are fed through waveguides 5, 6, 7 and 8. Different internal cross-sectional shapes and cross-sectional dimensions are adopted in the two diplexers (3,4) to ensure that the waves, on the one hand, do not mutually interfere and, on the other hand, propagate in the correct direction. As described, the front part of diplexer 3 has a circular cross-section, the second part has a cross-section which is smaller and somewhat rectangular, whilst the cross-section of the diplexer 4 is circular and even smaller. <IMAGE> |
