Patent ID: 9048536
Filing Date: 2015-06-02
Classification: H01Q,H04B

Abstract:
1. A mobile communication device comprising: an antenna; a power amplifier; a tunable matching circuit coupled between the antenna and the power amplifier, determining an output impedance encountered by a radio frequency (RF) signal transmitted by the power amplifier to the antenna when the RF signal enters the tunable matching circuit; a power detection circuit coupled between the antenna and the power amplifier, detecting a forward power of the RF signal entering the antenna and a reflected power of the antenna; and a controller coupled to the tunable matching circuit and the power detection circuit, tuning the tunable matching circuit according to a frequency range currently used by the mobile communication device, the forward power and the reflected power to steer the output impedance toward a corresponding load-pull impedance that the power amplifier has in the frequency range, wherein the controller tunes the tunable matching circuit according to the frequency range, the forward power and the reflected power to steer the output impedance toward the load-pull impedance when a strength of a signal from a base station is smaller than a threshold value.