Apparatus for controlling impedance in adaptive tuning antenna circuit

摘要

An apparatus for controlling impedance in an adaptive tuning antenna circuit is disclosed, wherein a matching unit is connected to an output terminal where a coupler outputs a coupled power of a transmission signal, a controller adjusts an impedance of the matching unit to cause the reflected power outputted by the coupler to be minimized, and the controller adjusts an impedance of a tuner to allow a combined impedance of the tuner and an antenna to be equal to the impedance of the matching unit but with opposite phases, thereby adjusting the impedance of the antenna in the optimal state.

主权项

1. An apparatus for controlling impedance in an adaptive tuning antenna circuit, the apparatus comprising:
a coupler configured to output an inputted transmission signal to a transmission signal output terminal, to output a coupled power of the transmission signal to a coupling power output terminal, to output a reflected power to a reflected power output terminal; a tuner configured to control an impedance of an antenna and to supply the transmission signal outputted by the coupler to the antenna; a matching unit configured to be matched to the coupled power outputted by the coupler; a power detector configured to detect a level of the reflected power outputted by the coupler; and a controller configured to control an impedance of the matching unit by tracing a position of an impedance capable of minimizing the level of reflected power detected by the power detector, and control the impedance of the antenna based on an impedance of the matching unit, wherein the matching unit comprises: a pin diode connected to the coupling power output terminal by an anode of the pin diode, wherein a radio frequency (RF) impedance of the pin diode is changed by control of the controller; a varactor connected to the coupling power output terminal by a cathode of the varactor, connected in parallel to the pin diode, wherein a capacitance of the varactor is changed by control of the controller; and an inductor connected in series to an anode of the varactor.