Antenna unit for portable wireless apparatus.

摘要

An antenna for portable wireless apparatus as shown in Figure 5 is capable of operating satisfactorily when an antenna element (8) is extended out of a case (7) or stowed in the case (7). A portion (8a) of the antenna element (8) not stowed in an antenna stowage pipe (12) when the antenna is pushed into the plastic case, functions as a radiation element. A portion of the antenna element and the antenna stowage (12) pipe produced of a metal for stowing this portion constitute an impedance stub circuit. Antenna impedances of the antenna element in the extended and stowage positions as well can be made approximately the same by properly setting the length of the antenna element which is stowed in the antenna stowage pipe and the length of the portion not stowed in the stowage pipe. <IMAGE>