| 摘要 |
PURPOSE:To provide a selective call radio receiver in which spurious radio wave radiation is reduced, its operation is stable and which is proper to miniaturization and cost reduction. CONSTITUTION:A printed circuit board 107 with a receiver circuit component 108 mounted thereon is sandwiched between a couple of conductor plates 106, 110 and the conductor plates 106, 110 are tightened by a screw 103 and a nut 104 to form an electromagnetic shield case for the circuit component 108 thereby reducing spurious radio wave radiation from the printed circuit board mounted circuit 108, especially from its local oscillation circuit to an external device. Furthermore, a ground plate for a microstrip antenna 1 is connected to the conductor plate 106 in terms of high frequencies to allow the conductor plate 106 to act like a ground plate of the antenna 1, then the microstrip board is made small thereby increasing a container volume of components to a receiver. Moreover, the antenna directivity pattern is made stable by providing a ground conductor part around the antenna element.
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