| 摘要 |
An antenna system for a portable radiotelephone which does not require an expensive mechanical and bulky change-over switch to switch between the transmitting and receiving main antenna element and the call signal-receiving sub-antenna element. This is accomplished by a rod-shaped transmitting and receiving main antenna element within an antenna retaining mechanism so designed that the antenna element is free to slide in and out of the case of the radiotelephone. This case also houses a sub-antenna element which is in constant electrical contact with the antenna retaining mechanism. Conductive components in the elements provide the switching function, and one of them, a conductive tube, is constantly connected to the transmitter-receiver set in the case so that there is no deterioration of the characteristics of the main antenna element.
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