US Patent 7299015 Transmission output control circuit, and wireless device using the same

According to a transmitting output control circuit, one end of a coupling capacitor and one end of main line of a directional coupler are coupled with an output terminal of a power amplifier. A switch for coupling the other end of the coupling capacitor and one end of a sub line of the directional coupler with an anode of a first diode or a second terminating resistor is formed in a power amplifying apparatus. Any one of the coupling capacitor and the directional coupler is coupled by switching the switch. By using this structure, the stable transmitting power control circuit, which can be used in a wide dynamic range necessary for detecting a transmitting output signal level, can be provided.