| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a large high frequency power device capable of preventing destruction of a last stage power amplifier due to a reflected wave power without deteriorating a high frequency power outputted from an antenna. <P>SOLUTION: The large high frequency power device includes an amplifying part for amplifying a high frequency power to output the same, a variable impedance matching part provided on an output side of the amplifying part and changing an input impedance based on a controlling signal to output a high frequency power, an antenna for outputting the high frequency power, a quadrature detection part outputting a common mode and a quadrature detection output signal by conducting a quadrature detecting of the reflected wave power from the antenna by the high frequency power input to the amplifying part, and a controlling part generating a controlling signal in response to the common mode and the quadrature detection output signal and sending out it to the variable impedance matching part. The controlling part, based on phase information of the reflected wave power obtained from the common mode and the quadrature detection output signal, generates a controlling signal for changing a phase shift volume in a transmission passage of the variable impedance matching part so that the phase of the reflected wave power may stay in a predetermined range. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
