IWR6843: Regulation in the 60 GHz band

Hi Charles,

Thank you for the info. I will look at the specs you mentioned as well.

Just to make sure I understand it correctly, are you going to provide further information on the 60 GHz power restrictions for the US after you hear from your team? If so, I will await your response on that.

By the way, one thing I observed related to the IWR6843 is its transmit power is 2 dBm lower than its 77 GHz counter part (IWR1642). I presume this reduced level may have something to do with the power restriction you mentioned for the 60 GHz band.

Regards,

Cagri

Hi Charles,

Thank you for the clarification.

I read the FCC 15.255 for the 60 GHz power limitations. Since I will be focusing on indoor sensing applications, my understanding is the total transmitted power shall not exceed 10 dBm in my case. Since IWR6843 TX power is 12 dBm, a power control is required to be able to work with this part. I had a search on the forum and located the thread below, which you will recognize. It seems power backoff is what I will need to reduce the transmit power.

By the way one part I could not understand in the below thread is why 3 transmit antennas EACH with 10 dBm output gives an EIRP of 23.7 dBm. If you could clarify that calculation, that will be helpful. If there are additional threads that you think will be helpful for me on this topic (i.e. tx power control, total EIRP power calculation etc.), I would appreciate it if you could share those also.

Regards,
Cagri

Hi Charles,

Thank you for your note and the pdf guide. These are really helpful.

Regarding the relevant clause you mentioned, since my application's bandwidth will not only occupy the 500 MHz within the 61.0 - 61.5 GHz band, clause (3) will be relevant I think (I included them below for our reference). The latter part of clause (2) is referring to transmission outside of the actual bandwidth it seems. However, clause (3) covers applications that span a much wider bandwidth than the 500 MHz (mentioned in clause (2) ) 

I will review the information you shared on the power back off as well and try to digest it in the meantime. I will include additional questions, if any.

Regards,

Cagri

(2) For fixed field disturbance sensors
that occupy 500 MHz or less of band-
width and that are contained wholly
within the frequency band 61.0–61.5
GHz, the average power of any emis-
sion, measured during the transmit in-
terval, shall not exceed 40 dBm, and
the peak power of any emission shall
not exceed 43 dBm. In addition, the av-
erage power of any emission outside of
the 61.0–61.5 GHz band, measured dur-
ing the transmit interval, but still
within the 57–64 GHz band, shall not ex-
ceed 10 dBm, and the peak power of any
emission shall not exceed 13 dBm.

(3) For fixed field disturbance sensors
other than those operating under the
provisions of paragraph (b)(2) of this
section, the peak transmitter con-
ducted output power shall not exceed
10 dBm and the peak EIRP level shall
not exceed 10 dBm.