| 摘要 |
An inexpensive, efficient, broadband, slot-type antenna with unidirectional sensitivity includes a slot-forming means defining a plurality of substantially concentric and generally coplanar annular slots and a non-resonant antenna connection means for transmitting electromagnetic energy to and from the plurality of annular slots. The antenna connection means forms a plurality of non-resonant, radially-extending cavities that are adapted to combine electromagnetic energy received at a plurality of concentric annular slots for transmission from the slots generally in phase and along the central slot axis that lies perpendicular to the two concentric annular coplanar slots. The antenna may also include a plurality of impedance-forming portions distributed around the periphery of at least one or two of the substantially concentric annular slots to enhance both left-handed and right-handed circular polarization, to provide dual linear polarization, and enhance the unidirectional sensitivity of the antenna. Such a plurality of impedance-forming portions may be formed by the slot-forming means as openings or slots at a plurality of locations around one or two of the concentric annular slots and oriented and distributed around their peripheries to correct for variations to polarity and to suppress sideband energy to and from the antenna.
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