Claims: 1. A mobile phone device, comprising:
a baseband processor;
an antenna for receiving and sending a plurality radio frequency signals;
a duplexer electrically connected to the antenna; and
a radio frequency transceiver circuit connected to the baseband processor and the duplexer, respectively, the radio frequency transceiver circuit comprising:
a first power amplifier having a first output impedance; and
an impedance adjusting device electrically connected between the first power amplifier and the duplexer, wherein the impedance adjusting device comprises at least one switch; and
wherein the baseband processor is connected to and control the at least one switch of the impedance adjusting device to adjust an impedance value of the impedance adjusting device, such that a first load impedance of the first power amplifier and the first output impedance match one another.
, Description:TECHNICAL FIELD
The present invention relates to an impedance adjusting device, and particularly relates to an impedance adjusting device applied in matching different power amplifiers.

BACKGROUND
In a common mobile communication device, matching impedance networks of a power amplifier, such as a broadband pulse amplitude modulation power amplifier, in a radio frequency circuit are all paired in a customized manner. Once there is a need for a replacement with a different power amplifier, the customized matching impedance network also needs to be replaced accordingly, which increases the production cost. In view of this, the present invention proposes an impedance adjusting device and a mobile phone device applying the impedance adjusting device.

SUMMARY
An embodiment of the present invention provides a mobile phone device. The mobile phone device comprises a baseband processor, an antenna, a duplexer and a radio frequency transceiver circuit. The antenna is used to receive and send a plurality of radio frequency signals. The duplexer is electrically connected to the antenna. The radio frequency transceiver circuit is connected to the baseband processor and the duplexer, respectively. The radio frequency transceiver circuit comprises a first power amplifier and an impedance adjusting device.The first power amplifier has a first output impedance. The impedance adjusting device is electrically connected between the first power amplifier and the duplexer, and comprises at least one switch, wherein the baseband processor is connected to and control the at least one switch of the impedance adjusting device to adjust an impedance value of the impedance adjusting device, such that a first load impedance of the first power amplifier and the first output impedance match one another.