MC7475 Module FCC MPE Evaluation_R

FCC ID: N7NMC7475

RF Exposure Info

Download: PDF
FCCID_3569784

 MPE Evaluation for
MC7475 Radio Module

      September 19, 2017


1. Introduction
     In this application we seek modular approval for the MC7475 radio module
     for use in standalone and collocated simultaneous transmission under
     mobile and fixed configurations. This Maximum Permissive Exposure
     (MPE) report demonstrates compliance analysis for MC7475 radio module
     with FCC CFR 47 §2.1091 and IC RSS-102 for standalone and collocated
     transmission in the exposure conditions where a separation distance of at
     least 20 centimeters is normally maintained between the transmitter's
     radiating structure(s) and the body of the user or nearby persons. The
     MPE analysis is limited for US / Canada bands only.

     The general population/uncontrolled exposure limits are applicable to
     situations in which the general public may be exposed or in which persons
     who are exposed as a consequence of their employment may not be
     made fully aware of the potential for exposure or cannot exercise control
     over their exposure.


2. RF Exposure Limits and Equations
     FCC Limits:

     According to FCC OET Bulletin 65 Supplement C, the criteria listed in
     Table 1 shall be used to evaluate the environmental impact of human
     exposure to radio frequency (RF) radiation as specified in §1.1307.




             Table 1 : Limits for Maximum Permissible Exposure (MPE)

     IC Limits:

     IC has adopted the RF field strength limits established in Health Canada’s
     RF exposure guideline. The limits are shown in Table 2 below per RSS-
     102.


       Table 2 : RF Field Strength Limits for Devices Used by the General Public
                              (Uncontrolled Environment)

      In the frequency range of 300-6000 MHz, the IC limits are more stringent
      than the FCC limits. The MPE evaluation in this report will be based on
      the IC limits, so the deduced output power and antenna gain limits will
      guarantee compliance with both FCC and IC requirements.


      EQUATIONS:

      EIRP (dBm) = Conducted Power (dBm) + Antenna Gain (dBi)

      Power density is given by :

              S = EIRP / (4 π * D^2)

      where
              S = Power density (mW/cm^2)
              EIRP = Equivalent Isotropic Radiated Power (mW)
              D = Separation distance (cm)


3. Stand-Alone Transmission
When MC7475 module transmits as a stand-alone mobile device, the source-
based time-averaged EIRP is calculated by summing up conducted power and
antenna gain. A 100% duty cycle is used for calculations to present a worse-case
analysis. The antenna gains are chosen so that the resulted radiated power
levels are within the limits specified by the FCC rules and IC Radio Standards
Specifications (RSS). The IC exemption limits for routine RF exposure


evaluation are calculated using the lowest frequency of the operating band
presenting the most stringent limits.

As shown in Table 2 below, the resulted EIRP are always below the IC
exemption limits for all the operating modes.

                                                                        Source-
                                           Max                                         IC
                                                               Max       Based
                                        Time-Avg   Max Time-                      Exemption   EIRP/ERP
                        TX Freq Range                           Ant      Time-
    Operating Mode                         Cond    Avg Cond                          Limit      Limits
                            (MHz)                              Gain    Averaged
                                         Power     Power (W)                        (EIRP)
                                                               (dBi)   Max EIRP
                                          (dBm)                                     (dBm)
                                                                         (dBm)
                                                                                               2W
    LTE Band 2         1850 1910          24        0.25        6        30        33.50
                                                                                               EIRP
                                                                                               1W
    LTE Band 4         1710 1755          24        0.25        6        30        33.27
                                                                                               EIRP
                                                                                               3W
   LTE Band 12         699      716       24        0.25        6        30        30.61        ERP
                                                                                              0.25 W
   LTE Band 125        2315 2318          14        0.20       10        24        34.17       EIRP

                     Table 2: MC7475 Stand-Alone Transmission


4. Collocated Transmission
When MC7475 module co-transmits with radio transmitter(s) as a mobile device,
per KDB 447498 D01, simultaneous transmission MPE test exclusion applies
when the sum of the MPE ratios for all simultaneous transmitting antennas
incorporated in a host device, based on the calculated/estimated, numerically
modeled or measured field strengths or power density, is ≤ 1.0.

The evaluation here considers a WiMAX or WLAN transmitter, and a Bluetooth
transmitter as collocated transmitters. Their radiated output power levels are
listed in Table 3 below. The MPE ratio is defined by the ratio of power density to
MPE limit. The sum of the MPE ratios is calculated as follows:

 ∑𝑀𝑃𝐸 𝑅𝑎𝑡𝑖𝑜 = Max (MC7475 MPE ratio) + Max (WLAN/WiMax MPE ratio) + BT
                       MPE Ratio
                     = 0.864+0.121+0.012=0.997 < 1.0

                                           Max     Max             Source-
                                          Time-   Time-   Max       Based     Power
                                                                    Time-                IC MPE       IC
                          TX Freq Range     Avg     Avg    Ant                Density
    Operating Mode                                                Averaged                Limit   PwrDensity
                              (MHz)        Cond    Cond   Gain                @20 cm
                                                                  Max EIRP              (W/m2)    MPE Ratio
                                          Power   Power   (dBi)              (W/m^2)
                                          (dBm)     (W)            (dBm)


    LTE Band 2           1850     1910     24     0.25     6        30        1.99      4.48       0.444

    LTE Band 4           1710     1755     24     0.25     6        30        1.99      4.24       0.469
   LTE Band 12            699      716     24     0.25    6         30        1.99      2.30       0.864
  LTE Band 125           2315     2318     14     0.20    10        24        3.15      5.49       0.574
  WLAN 2.4 GHz           2400     2500                              23        0.40      5.35       0.074
  WLAN 5 GHz             5150     5850                              23        0.40      9.01       0.044
                         2300     2400                              25        0.63      5.19       0.121
      WiMAX              2500     2700                              25        0.63      5.50       0.114
                         3300     3800                              25        0.63      6.65       0.095
         BT              2400     2500                              15        0.06      5.35       0.012

                      Table 3: MC7475 Collocated Transmission

5. Conclusion

   The analysis presented in this report concludes that the MC7475 radio
   module, when transmitting either in standalone or simultaneously with other
   co-located radio transmitters within a host device, is compliant with the
   FCC/IC RF exposure requirements in mobile exposure condition, provided the


conducted power and antenna gain do not exceed the limits in Table 4 for
each given frequency band and operating mode.

                                                                       Antenna
                                                          Max Time-              EIRP Limits
                                         TX Freq Range                   Gain
                       Operating Mode                     Avg Cond                 (dBm)
                                             (MHz)                      Limits
                                                         Power (dBm)
                                                                         (dBi)


                       LTE Band 2       1850     1910       24           6          30
       MC7475




                       LTE Band 4       1710     1755       24           6          30
                       LTE Band 12       699      716       24           6          30
                      LTE Band 125      2315     2318       14           10         24
                      WLAN 2.4 GHz      2400     2500                               23
   Collocated Radio
     Transmitters




                      WLAN 5 GHz        5150     5850                               23
                                        2300     2400                               25
                         WiMAX          2500     2700                               25
                                        3300     3800                               25
                            BT          2400     2500                               15


                         Table 4: MC7475 RF Exposure Conditions



Document Created: 2017-09-19 12:19:32
Document Modified: 2017-09-19 12:19:32

© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC