Summarized reasons why the metallic-floor type EMC test site depends on uncertain measure: technical problems in common with both sites for measuring radiation disturbance and for calibrating antennas

摘要

Development of highly versatile portable telephone as a leading player in the IT era continues at present. Promotion of its normal development assumes undoubtedly the EMC with office automation equipment5 ISM equipment and so on, and the safety of human body. Therefore, CENELEC has officially adopted the free-space type test site and the international recommendations may be issued through CT SPR shortly. On the other hand in Japan, the reflective metallic floor type test site is still being used over the frequencies below 1 GHz (ARIB STD-T57/1999-10). This may fall Japan behind in the international competition, if no timber action is taken. This paper shows that the metallic floor type test site uses an uncertain measure through which figures obtained of the field strength undergo a change of 10 to 30 dB depending on the test conditions. As a result, even the conversion of radiated power of disturbance, being a basis of assessing safety level to human body becomes impossible. And the paper summarizes clearly that such deficiency is found in the test site for antenna calibration as well.