Patent ID: 9166551
Filing Date: 2015-10-20
Classification: H03H,H04B

Abstract:
1. An apparatus for matching impedance using Standing Wave Ratio (SWR) information, the apparatus comprising: a directional coupler extracting forward power of a transmission signal traveling to be transmitted through an antenna, and reflected power of the transmission signal reflected from the antenna; an impedance matching unit matching impedance of the antenna by varying impedance according to a control signal, wherein the impedance matching unit includes a variable capacitor; a forward power detection unit detecting the forward power from an output signal of the directional coupler; a reflected power detection unit detecting the reflected power from the output signal of the directional coupler; a SWR operation unit calculating a SWR by using the forward power detected by the forward power detection unit and the reflected power detected by the reflected power detection unit; and an impedance control unit determining whether an initial total impedance of the impedance matching unit and the antenna is located in a region of a plurality of regions of a Smith chart representing impedances of the impedance matching unit and the antenna by using dependencies of changes of SWR values calculated by the SWR operation unit upon changes of capacitance values of the variable capacitor, and changing the capacitance values of the variable capacitor of the impedance matching unit according to the determined region to control impedance of the antenna to be matched; wherein the region of the Smith chart is divided into first to sixth sub-regions (T wherein a first sub-region (T wherein the impedance circle (