| 摘要 |
1,225,085. Aerials. ROHDE & SCHWARZ. 28 July, 1969 [8 Oct., 1968], No. 37759/69. Heading H4A. In an aerial of the backfire type, comprising an end-fire array having a main reflector at one end and an auxiliary reflector at the other end, one or more active elements are incorporated directly in said end-fire array. As described, an aerial comprises a flat surface main reflector 1, Fig. 2, and an auxiliary reflector 2 formed, for example, by individual rods or by a circular metal disc, and at a distance L 2 from the reflector 1, which provides resonance at the lower end of the operating frequency band. A feed dipole 4 is near the main reflector 1, and incorporates an active element 5, such as an amplifying transistor. Between the dipole 4 and the auxiliary reflector 2 are director elements 3 and an additional element 6, next to the reflector 2, which incorporates an electronically controllable active element 7, such as a diode or a transistor. The element 6 is at a distance L 1 from the reflector 1 and when it is made fully reflective by suitable adjustment of the voltage upon the active element 7, it provides resonance at the upper end of the operating frequency band. For other voltages upon the active element 7, the element 6 is partially reflective, and resonance is obtained at intermediate frequencies within the operating frequency band. In another embodiment, a feed dipole (4), Fig. 1 (not shown), incorporating an active element (5), is placed near an auxiliary reflector (2), and the aerial further comprises only director elements (3) and a main reflector (1). |
