MPE Calculation

FCC ID: 2ABCB-RPI4B

RF Exposure Info

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FCCID_4325665

Page 1 of 3 MPE Calculation — FCC ID :2ABCB—RPI4B The FCC requires that the calculated MPE be equal to or less than a given limit dependent on frequency at a distance of 20 cm from a device to the body of a user. The transmitter operation for the Raspberry Pi 4 covers the 2.4GHz and 5GHz operating bands. Simultaneous transmission is not supported between any of the transmitters The following FCC Rule Parts are applicable: Part 1.1310 —— Radiofrequency radiation exposure limits Part 2.1091(c) — Radiofrequency radiation exposure evaluation: mobile devices CALCULATION The following far field power density equation is applicable: $ = EIRPMA m R@ Where S = Power density EIRP = Effective Isotropically Radiated Power (EIRP =P x G) P = Conducted Transmitter Power G = Antenna Gain (relative to an isotropic radiator) R = distance to the centre of radiation of the antenna (safe operating distance) Calculation for 2.4GHz BT (BDR/ EDR worst case): Values: Transmitter frequency range =2402 — 2480MHz P = 4.8dBm G = 3.5dBi (x 2.24) EIRP = 8.3dBm (6.76mW) R =20cm Power Density Requirement From table 1 (b) — Limits for General Population/ Uncontrolled Exposure of FCC Rule Part 1.13140 for 2.4GHz Sreqt = 1.0 mWicm?

Page 2 of 3 Calculation: 5 = EIRPM TR =6.76/(12.56 x 20°) = 6.76/(5024) $, = 0.0013 (Equivalent to 0.73cm safe operating distance) Calculation for 2.4GHz WLAN Values: Transmitter frequency range =2412 — 2462MHz P = 13.4dBm G = 3.5dBi EIRP = 16.9dBm = 49.0mW Power Density Requirement From table 1 (b) — Limits for General Population/ Uncontrolled Exposure of FCC Rule Part 1.1310 for 1900MHz for 2.4GHz Sreqa = 1.0 mWicm* Caloulation: S = EIRPM 1 R® =49/(12.56 x 20°) =49/(5024) S = 0.0097 (Equivalent to 2.0cm safe operating distance)

Page 3 of 3 Calculation for 5.0GHz WLAN Values: Transmitter frequency range =5170 — 5825MHz P = 14.5dBm G = 2.30Bi EIRP = 16.8dBm = 47.9mW Power Density Requirement From table 1 (b) — Limits for General Population/ Uncontrolled Exposure of FCC Rule Part 1.1310 for 1900MHz for 5GHz Sreqs = 1.0 mW/icm* Calculation: 8 = EIRPM tm R = 47.9/(12.56 x 202) =47.9/(5024) S; = 0.0095 (Equivalent to 1.95c0m safe operating distance) Conclusion The required 200m RF exposure limits for General Population/ Uncontrolled Exposure FCC Rule Part 1.1310 limits will not be exceeded for the Raspberry Pi 4 using antennas having a maximum gain of 3.5dBi (2.4GHz) and 2.3dBi (5GHz). af


Document Created: 2019-06-17 17:25:18
Document Modified: 2019-06-17 17:25:18
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