PURPOSE: To enable to obtain the speed measurement of high reliability from low to high speed under the mounting on automobiles, by providing the shield cover giving attenuation effect only to the side lobe of antenna.
CONSTITUTION: It is important to avoid the side lobe of vertical direction to increase the accuracy of speed detection as a speedometer. Thus, the shield cover 9 is fixed on the existing radar unit 2 with the fixed screw 3. That is, the electromagnetic wave absorbing plate 10 such as rubber-ferrite is placed inside the cover 9 to attenuate the side lobe (especially, vertical side lobe) caused without giving effect on the main lobe radiated from the horn antenna 4, allowing to use the antenna only with the main lobe 3 in fact. Further, the cover 9 is provided with the opening 91 for the main lobe 5, where dielectric substance plate ("Teflon ") 11 is provided, small in high frequency loss, as dust and water proof provision.
KIMURA KATSUHIRO
SEKINE KENJI
HITACHI LTD