| 摘要 |
An efficient antenna pattern shaping structure employs a parasitic element made of a conductive surface next to radio circuitry to shape the pattern of an associated antenna, preferably one that is a quarter wave antenna. The parasitic element is disposed on a first side of the radio circuitry to act as a reflector of electromagnetic energy. The parasitic element has at least two edges and wherein the at least two edges of the parasitic element are bent in a direction towards the radio circuitry in order to shape the antenna pattern more efficiently. The parasitic element is electrically slightly larger than a half wavelength of a frequency band of interest, preferably the low frequency of interest. A optional opposing parasitic element can be disposed on a second side of the radio circuitry opposite the first side. The opposing parasitic element is electrically slightly smaller than a half wavelength of the frequency band of interest, preferably half a wavelength of the high frequency of interest. A conductive surface, having bends at the ends and preferably grounded, on a side of a wiring board of the radio circuitry, can be used in addition to or instead of an independent parasitic element.
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