| 摘要 |
<p>A planar antenna includes a first slotted waveguide (12, 52) serving as a power-feed unit, and a second slotted waveguide (14, 54) of planar type coupled with the power-feed waveguide (12, 52), for radiating circularly polarized microwaves into space. The second waveguide (12, 52) has a metal plate in which a two-dimensional slot array consisting of a plurality of rows of slots (16) is formed. An insulative layer (30, 62) is provided on the second waveguide (12, 52) to cover the slot array (16). A plurality of rows of metal patch radiators (18) are provided on the insulative layer (30, 62). These patch radiators (18) are electromagnetically coupled with the slots (16), respectively, in such a manner that each radiator (18) is directly excited by the corresponding slot (16) through the insulative layer (30, 62), thereby radiating circularly polarized microwaves.</p> |
