公开(公告)号：EP0228131A3

公开(公告)日：1988-03-02

申请号：EP86202287

申请日：1986-12-16

申请人： PHILIPS ELECTRONIC AND ASSOCIATED INDUSTRIES LIMITED ,  N.V. Philips' Gloeilampenfabrieken

发明人： Gibson, Peter John

IPC分类号： H01Q13/20 ,  H01Q21/06 ,  H01Q01/38

CPC分类号： H01Q21/068 ,  H01Q13/206 ,  H01Q21/0075

摘要： A generally planar antenna formed in strip transmission line comprises a two-dimensional array of antenna elements (11) coupled to a plurality of secondary feeders (10) each coupled at at least one end to a primary feeder (4). In order that the level of coupling between the primary feeder (4) and each secondary feeder (10) should be well-defined and, when there is a large number of elements, suitably low, the coupling means therebetween are shielded and non-conductive, suitably a directional coupler (17). To provide the shielding, the primary feeder (4) and coupling means may be formed in double-ground-plane line. In an arrangement suitable for an antenna wherein power may be supplied to either end of the primary feeder (4) to give radiation patterns having single main lobes with different angular orientations, for example for a Doppler navigation system, one port of each directional coupler (17) may have an open-circuit reflective termination. For a simple design in which the proportion of power coupled into the secondary feeders (10) veries along the primary feder (4), the coupling value of the coupling means may vary stepwise from one group adjacent secondary feeders (10) to another.