Antenna Selection for PH8-P Module | Telit Cinterion IoT Developer Community
June 23, 2016 - 5:32pm, 2934 views
I'm trying to select an antenna for use with your PH8-P module and having some issues determining what antenna gain is acceptable. The application is a fixed application (not mobile).
Section 9.2 of the Hardware Interface Description document (April 2016) for the PH8-P module states that the antenna gain, including cable loss, must not exceed the limits 3.94dBi (850MHz) and 1.81dBi (1900MHz). The FCC grant states limits of 0.89dBi (850MHz) and 1.6dBi (1900MHz). Your FCC submitted MPE calculation documentation gives the following values: 0.89dBi (850MHz) and 6.16dBi (1900MHz).
Why are the values different for each of these documents?
In the MPE calculation, where is the maximum average output power at the antenna terminal information obtained from? For example, the calculation for the 850MHz band has a value of 33.59dBm. The HID document does not show this value. Section 2.1 of the HID specifies a 33dBm + 2dBm for this band. If I used 35dBm in the MPE calculation, this has a large impact on the allowable antenna gain.
Thanks in advance for you help.
Could you please specify all the documents names and versions from where you have taken the cited values so I could check and clarify this?
"Hardware Interface Document": PH8_PH8-P_HD_v03.001
FCC Grant and MPE Calculation were obtained from FCC website: https://apps.fcc.gov/oetcf/eas/reports/GenericSearch.cfm?calledFromFrame=N
I tried to hyperlink each document, but access was denied when trying to use the hyperlinks. If you enter in the FCC ID in the search, the documentation will be available. The MPE calculation documentation is under the "Details" section.
Thank you for the additional information. I'll try to clarify this and write back.
Indeed the values are different in the hardware description and FCC. I can't compare to previous releases because in hardware descriptions for previous releases there were no values listed at all. The measurements and MPE calculations are done by external company but 33.59dBm is in the range declared as 33dBm +-2dBm.
The most important is FCC grant and you should follow the rules and limits stated in the FCC grant:
Output power listed is peak conducted. This device contains functions that are not operational in U.S Territories. This filing is only applicable for US operations. This OEM module is approved for use in products operating as fixed or portable transmitting device. The antenna(s) used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any other antenna or transmitter. A separate approval is required for portable operating configurations, as defined in 2.1093 of the rules. The final product operating with this transmitter must include operating instructions and applicable warnings for endusers and installers to satisfy RF exposure compliance requirements. Antenna gain must meet RF exposure and *** radiated output power limits of the applicable rule section. This Grant is valid only when the device is sold to OEM integrators and the OEM integrators are instructed to ensure that the end user has no manual instructions to remove or install the device. The ***. antenna gain for this device as reported to the FCC is: 0.89 dBi (850MHz) and 1.6 dBi (1900MHz).
Thank you for the information. I have one additional question.
If I use the diversity antenna feature of the module, are there any antenna characteristics that must be considered for this additional antenna to not violate FCC compliance?
My interpretation of the grant statement "The antenna(s) used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any other antenna or transmitter." is that it is about one antenna or antennas which should not be in conjunction or co-located with any other antenna or transmitter.
I can't see any other reference for more antennas so would I assume that the same rules applies for one antenna and two antennas.