I am looking into a possibility for 60GHz energy harvesting for low power sensor nodes and I am little confused about the differences I have found between the US and European regulations related to 60GHz RF output power. FCC states in II/4. that 40dBm average EIRP is allowed. On the other hand ETSI makes difference between indoor and outdoor values, and also specifies the maximum power density. These lead to very different rules for two big markets, which I find confusing.
ETSI allows the same 40dBm for indoor communication, but allows only 13, and -2 dBm/MHz spectral power density for indoors and outdoors respectively. This is equivalent to 27dB and 42dB lower power for a continuous wave, and makes energy transfer infeasible in Europe. Here of course I've assumed that the ETSI standard is applied across Europe.
A third value - without reference - was 20dBm EIRP, stated in this paper, which increased my confusion further.
One question is whether my understanding above is correct, and such difference exists in the regulations, or I did not found some other regulation which extends or overwrites those above. And the related other one is: What is the allowed maximal output power, or EIRP in the US and in the EU for a continuous wave?
Revision of Part 15 of the Commission’s Rules Regarding Operation in the 57-64 GHz Band, Federal Communications Commission (FCC) Std., Aug. 2013.
Broadband Radio Access Networks (BRAN);60 GHz Multiple-Gigabit WAS/RLAN Systems; Harmonized EN covering the essential requirements of article 3.2 of the R&TTE Directive, European Telecommunications Standards Institute (ETSI) Std. EN 302 567, Rev. 1.1.0, 2009.
C. Bredendiek, D. A. Funke, J. Schopfel, V. Kloubert, B. Welp, K. Aufinger, and N. Pohl, “A 61-GHz SiGe Transceiver Frontend for Energy and Data Transmission of Passive RFID Single-Chip Tags With Integrated Antennas,” IEEE J. Solid-State Circuits, vol. 53, no. 9, pp. 2441–2453, 2018.