| 摘要 |
The problem of reducing the size of a dual offset Cassegrain reflector type microwave antenna without adversely affecting performance while retaining the simplicity of the main reflector's (1) and subreflector's (3) traditional simple surface curvatures is solved by having the paraboloidal shaped main reflector's focal length, fm, and diameter, D, fulfil the criteria that the ratio of fm to D is less than 1.0; and in which the hyperboloidal shaped subreflector (3) is oriented so that its left foci, at which the microwave feed (5) aperture is placed, lies above the main reflector's focal axis. It's subreflector subtends an angular arc about the focal point that is slightly larger than the corresponding arc subtended by the main reflector. The elegance of the compact antenna is demonstrated by improved performance, attaining efficiencies in excess of seventy three percent.
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