| 摘要 |
PURPOSE: An impedance matching device is provided to perform optimal impedance matching by controlling input impedance to coincide with characteristic impedance of a directional coupler. CONSTITUTION: A directional coupler(420) separates a transmission signal inputted from a power amplifier and a reflection signal reflected from an antenna and outputs the signals. A detection unit(440) detects transmission power from the outputted transmission signal. The detection unit detects reflected power from the separated reflection signal. A first variable matching unit(410) controls impedance based on intensity of the detected transmission power and reflection power. A second variable matching unit(430) controls input impedance measured when looking from the directional coupler to the power amplifier. [Reference numerals] (200) Power amplifier; (410) First variable matching unit; (420) Directional coupler; (430) Second variable matching unit; (441) Transmission detection unit; (442) Reflection detection unit; (450) Analog to digital convertor; (460) Control unit; (470) Saving unit
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