Study on the Impact of the RF Output Power in EMC Tests of Radio Equipment

In this paper, the effects of radio frequency output power level on Electromagnetic Compatibility tests of wireless radio equipment are analyzed. In EMC tests of radio equipment, the RF output power level should be set to maximum according to ETSI EN 301 489 standards. However, this test condition is not operable in the application of the tests covered by these standards. In order to meet these test conditions, it is necessary to provide certain requirements such as additional board and special software by the manufacturer of the chip which is essential part of the radio equipment for establishing the wireless communication in radio spectrum. This test situation would be practicable for board based modular wireless equipment such as Bluetooth, Wi-Fi. As for application of the tests with combined equipment, set the RF output power to the maximum is not feasible at all times. Because the radio parts are inside of enduser combined test equipment such as washing machines or laptops with Wi-Fi communication, televisions have built-in Bluetooth. The tests are performed at three different RF output power levels; minimum, medium and maximum. The differences between the measurement results are evaluated for these three RF output power levels by taking into account the measurement uncertainty.