Polarized wave measuring apparatus, and antenna characteristic measuring apparatus and radio wave measuring apparatus using the same

A polarization measuring method comprising:

• a receiving step of receiving radio waves through a first antenna and second antenna whose planes of reception polarization are orthogonal to each other;
• a band restricting step of attenuating any component other than a desired frequency component from a first received signal received from said first antenna and a second received signal received from said second antenna;
• a first mixing step of mixing said first received signal and said second received signal to generate a first mixed signal;
• a second mixing step of mixing said first received signal and the second received signal which is phase-shifted by one-quarter wavelength to generate a second mixed signal;
• a low pass filtering step of eliminating high-frequency areas other than a baseband area from said first mixed signal and said second mixed signal;
• a phase difference calculating step of calculating a phase difference between said first received signal and second received signal from the first mixed signal and second mixed signal stripped of the high-frequency areas;
• a field intensity measuring step of measuring the field intensities of said first received signal and said second received signal with components other than the desired frequency component attenuated;
• and
• a polarization calculating step of calculating polarization of the received signal from the field intensities of said first received signal and second received signal and said phase difference.