| 摘要 |
PURPOSE:To provide the power amplifier circuit for a portable telephone formed inexpensively with simple configuration. CONSTITUTION:The circuit consists of a main body 100 and an adaptor 200. The main body 100 is provided with an amplifier means 43 amplifying a sent high frequency signal, a power detection means 45 detecting an output level of the amplifier means 43, an output control means 60 keeping an output level of the amplifier means 43 to be a prescribed level based on the detection output of the power detection means 45, an output variable means 70 revising the kept prescribed level, and a connection detection means 72 detecting whether or not the adaptor is connected to the main body. The adaptor 200 is provided with a linear amplifier 201 amplifying an output of the amplifier means 43 when the adaptor 200 is connected to the main body 100. When the adaptor 200 is connected to the main body 100 by a connection detection means 201, the output variable stage number by an output variable means 60 is changed from that when the adaptor 200 is not connected. |
