Electric wave receiving apparatus

An electric wave receiving apparatus to perform reception of an electric wave including a time code, comprising:

• an antenna that receives an electric wave;
• a tuning frequency switching circuit that enables a tuning frequency of the antenna to be switched into a plurality of kinds;
• a first amplifier that amplifies a signal received by the antenna;
• a plurality of filter circuits that make signals in different frequency bands correspondingly to the plurality of tuning frequencies pass from an output of the first amplifier;
• a third amplifier that amplifies outputs of the plurality of filter circuits;
• a first selecting switch that selects one of the outputs of the plurality of filter circuits and outputs the selected output to the third amplifier;
• a plurality of detector circuits that demodulate the time code from the output of each of the filter circuits through the third amplifier correspondingly to the plurality of filter circuits;
• a second selecting switch that outputs an output of the third amplifier to one of the plurality of detector circuits selectively;
• an automatic gain control circuit that generates a gain control signal indicating an average signal level of an output signal;
• a third selecting switch that selects one of output signals of the plurality of detector circuits to supply the selected output signal to the automatic gain control circuit;
• an arithmetic processing section that analyzes the time code by inputting outputs of the plurality of detector circuits;
• and
• a switching control circuit that controls switching of the tuning frequency switching circuit and the first to the third selecting switches respectively, wherein
• the switching control circuit controls the switching so that passing frequencies of the filter circuits connected to the third amplifier correspond to the tuning frequencies of the antenna;
• so that the filer circuits connected to the third amplifier correspond to the detector circuits;
• and so that the outputs of the detector circuits connected to the third amplifier are supplied to the automatic gain control circuit;
• in a state in which the tuning frequency switching circuit synchronizes with the first to the third selecting switches, and the switching is performed at a frequency higher than a data transmission frequency of the time code;
• and
• the arithmetic processing section selects an output to enable analysis of the time code out of each of the outputs of the plurality of detector circuits, and analyzes the time code from the selected output.