Patent ID: 7551908
Filing Date: 2009-06-23
Classification: H03G

Abstract:
1. A high-frequency signal level determining apparatus comprising: an AGC circuit for executing an automatic gain control on an intermediate frequency signal obtained by converting a frequency of a received high-frequency signal, using an RFAGC value for controlling a gain of the received high-frequency signal and an IFAGC value for controlling a gain of the intermediate frequency signal based on the intermediate frequency signal so that an output level of the intermediate frequency signal is substantially constant; and determining means for previously measuring first relational data indicating an RFAGC value relative to an inputted signal level of a generated high-frequency signal and second relational data indicating an IFAGC value relative to the inputted signal level of the generated high-frequency signal, for measuring the RFAGC value and the IFAGC value when a high-frequency signal to be measured is received, and for determining the inputted signal level of the received high-frequency signal using the measured first and second relational data based on the measured RFAGC value and IFAGC value, wherein the received high-frequency signal has a plurality of frequencies, and wherein said determining means previously measures a first relational data indicating the RFAGC value relative to the inputted signal level and a second relational data indicating the IFAGC value relative to the inputted signal level, using a generated high-frequency signal having a substantial central frequency among the plurality of frequencies.