3D角反射天线作馈源的5.8GHz偏馈抛物面天线.pdfVIP

3 D Corner Reflector Antenna as an efficient feed for offset parabolic antennas for 5.8 GHz Dragoslav Dobričić, YU1AW Abstract In this article I present a modification of 3D corner reflector antenna in order to adjust it for the use as a feed for SAT TV offset parabolic antennas on 6 cm Ham band or WLAN frequencies of 5.8 GHz. Introduction The problems that occur while illuminating shallow offset parabolas, in addition to those related to the efficient use of parabolic generally, are additionally aggravated by the specific geometry of the parabolic mirror itself. Feed positioning in the way that its phase center exactly coincides with the focus of the offset parabola and its direction so that the radiation maximum falls in the geometric center of the elliptic reflector surface are not intuitive at all, as in classic parabolic antennas. Therefore, there are a many confusions and wrongly positioned feeds that dont correctly illuminate offset a parabolic dish, decreasing its efficacy and gain. Classic and offset parabola A parabolic surface or paraboloid is formed by rotation of parabolic curve around its axis of symmetry. The specificity of the surface gained in this way is that when the beam of rays parallel to its axis of rotation falls on it, the beam is reflected so that all the rays meet in one point, known as the focus, in the same way that optical lenses focus light rays in their focus. 1 September2009 When the piece of a (mathematically infinite) surface of paraboloid is cut off, a parabolic reflector or mirror is gained. Cutting off (cropping) can be carried out in many ways, but all of them can be classified in two groups: those whose surface of cropping is perpendicular on the axis of symmetry, and those whose surface of cropping are