A speed measuring device that employs a Fresnel zone plate lens antenna. The Fresnel lens antenna is mounted to one end of a low profile collection housing, typically cylindrical in configuration. An opposite end of the collection housing includes a back plate having an opening. A transceiver unit is mounted to the outside surface of the back plate so that a transmitter and a detector within the transceiver are in communication with the opening. A signal is transmitted from the transceiver unit through the opening, and is directed by the lens antenna. A reflected signal is received and focused by the lens antenna, and collected by the housing to be directed through the opening to the transceiver.
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