Major changes :

Antenna Chnages Section:

• UNII devices - the lowest gain antenna in addition to the highest gain of each type are needed because the lowest gain results in worst case Radar reception. The addition of a lower gain antenna will require a Class II permissive change.
• For Ultra Wide Band (UWB) devices, all antennas affect emissions so all antennas need to be tested. The addition of an antenna will require a Class II permissive change.

• Transmitters subject to radiated power density limits and operating at or near the maximum power density level may need to reduce EIRP with lower gain antennas. This is for conditions when the radiated power density (V/m^2) is higher for lower gain antennas with less antenna surface area operating at the same EIRP levels require an evaluation to determine if a Class I or II is applicable.

Permissive Change and RF Exposure Section:

• Changes in antenna, and/or key radiating or metallic structures for portable devices require SAR evaluation to determine if a Class I or Class II permissive change is required.

  • SAR is primarily dependent upon the near fields and RF current distributions on a device; therefore, minor and simple metallic changes may cause relatively large changes in SAR.
  • Antenna gain is normally considered a far field parameter (e.g. Sections 15.31(f) and 2.1053(a), OET Bulletin 65, Section 2.1); however, SAR is primarily dependent on the near fields. SAR compliance considerations are separate from the Section 15.204 antenna gain provisions.

  • When adding an equivalent antenna for a part 15 device, i.e., identical antenna type with the same or lower gain, with no other change to the transmitter and host device configurations and the highest SAR measured for that antenna type in previous certification(s) is less than 0.8 W/kg, SAR evaluation is not required to add an equivalent antenna. Otherwise, SAR should be evaluated for the additional equivalent antenna(s) according to the procedures required for the transmitter, antenna and host device configurations.