EMI/EMC Testing

<Maxwell>

(3 meters Semi-anechoic chambers for radiated tests)

ECH Elektronikcentrum i Halmstad - 20150713 - joachimbrink - 012

 

<Faraday>

(chamber for conducted tests)

ECH Elektronikcentrum i Halmstad - 20150713 - joachimbrink - 025

EMC Testing of Wireless Devices

The most economical use of test time can be achieved by thorough preparation prior to the test or laboratory time. If the information of your device regrading the topics below will be informed to use will we have a better preparation in advance of testing, and, consequently, more-effective use of test time. The information you provide should include a thorough functional description of the product. The following parameters should be specified:

 

 

Preparation for the EMC Testing – (of Wireless Devices)

Radiated Emissions

  1. The radio’s software and / or firmware should be capable of the following operational modes. It is important to note that for each mode, continuous uninterrupted operation is required:
    • Transmit or receive continuously while operating at a single channel. For frequency hoppers, this means without the carrier hopping. The operating channel should be selectable from the lowest, middle, and the highest channels available. The transmitted carrier must be modulated. If a variety of modulation rates are available, they should be selectable from the lowest, middle and the highest modulation rates available. The data should be pseudo-random. All “1”s, all “0”s, or alternating “1010101…” could be worse case, but is not required by the regulatory agencies. If a variety of transmitted output power levels are available, they should be selectable from the lowest, the middle, and highest output power levels available.
  2. The highest gain antenna of each specified antenna type must be tested.
  3. Any ancillary equipment required to operate the radio such as personal computers should be dedicated for that use until testing is completed. If the radio has a wired interface (e.g. USB) with a personal computer, the radio will also be tested for compliance as a PC peripheral to the applicable ITE specifications. This testing requires the radio to be tested as part of complete PC system, so it is important to supply a PC (or notebook) that is known to have low emissions.

Antenna Port Emissions (specific wireless devices)

  1. The radio’s software and / or firmware should be capable of the following operational modes. It is important to note that for each mode, continuous uninterrupted operation is required:
    • Same mode required for radiated emissions (see above).
    • Also
    • For frequency hoppers, the hopping mode typical of normal operation. All hopping channels specified for normal operation must be used. If a variety of modes are available, they should be selectable.
  2. A provision should be made to allow the direct connection of the radio’s antenna port (RF output port) to a spectrum analyzer. This usually entails modifying a second unit (different than the radio used for radiated emissions testing). A standard female RF connector (e.g. SMA female) is soldered to the RF output port in place of the antenna.

Immunity Testing – (of Wireless Devices)

  1. European requirements include immunity testing with the radio both transmitting and receiving. The radio and associated equipment should be configured for typical operation and a means provided for monitoring the radio link. For example, in the case of a wireless network where the client radio is the equipment under test, it should be configured to continuously “ping” a remote access point. The pinging can be monitored to see if the link is degraded or broken as a result of the immunity test.