PD Simulation report_Appendix

FCC ID: IHDT56XL1

RF Exposure Info

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FCCID_4188340

Motorola Model: MD1005G FCC ID: IHDT56XL1 Appendix for 39 GHz Power Density Simulation and Measurement Report February 2019 Rev. 1.2 AR-19-0001a 1

1. Table of Contents Table of Contents 2 Appendix A: Block Diagram, Sensor-Based Measurement Planes, and 3D Simulation Models 3 Appendix B: Detailed Strategy for Finding Worst Case Beams 11 Appendix B1: Port Excitations in HFSS 12 Appendix B2: Material Properties in HFSS 14 Appendix C: Power Density and EiRP Results 15 2

Note on Right-Left Convention: Throughout this Simulation Appendix document, references to “right” or “left” side of the Mod device are given from the perspective of viewing the device from the back. 2. Appendix A: Block Diagram, Sensor-Based Measurement Planes, and 3D Simulation Models Block Diagram The RF block diagram of the device is shown in Figure 5.1.1, below. Figure 5.1.1: RF block diagram of the device. Measurement Planes In the following group of figures, the reduced measurement planes for each of the four mm-wave array modules, for each of the 5 mm-spaced or 2 mm-spaced overall measurement planes on the six sides of the device, are shown. These reduced measurement planes are the regions in which power density measurements are performed for each individual module, based on the operational characteristics of the proximity detection system, as described in the main report and Appendix B. The overall measurement planes are at a test separation distance of 5 mm on the six surfaces of the device, and at a 2 mm test separation distance (relative the host phone device) on the front surface. As discussed in the previous lab KDB inquiry, the 5 mm overall measurement planes are relevant to body-worn conditions, while the front-only 2 mm overall measurement plane is relevant to the at-head talk mode condition. As described in the main report, each module’s power density is measured in the applicable portions of those overall measurement planes, which are not excluded by the operation of the proximity sensor and power management system. For some modules (back, left, and right modules), the front surface measurements were performed only 3

on the 2 mm-spaced plane, since meeting the requirement at 2 mm implies also meeting the requirement at a larger spacing of 5 mm. For the back, left, and right modules, one respective 5mm-spaced overall measurement plane directly in front of the module, was excluded entirely from measurement, due to broad coverage of the proximity detection system in this “principal plane.” That is, the back 5 mm plane is excluded for the back module, left 5 mm plane is excluded for the left module, and right 5 mm plane is excluded for the right module. For the front-facing module, the 5 mm overall measurement plane is included in the measurement, since the detector cone for this module is not as broad due to partial blocking by the host phone device. However, for the front module, the plane at 2 mm spacing was excluded entirely, because the power management algorithm (as explained in Section 1.4.3.2 and Figure 1-4-10 of the Operational Description) entirely disables the front-facing module whenever the phone is operational in a talk-mode condition at the head (which is the use condition that the 2 mm-spaced front plane represents). Other than these excluded-per-module principal planes each module is measured in the non-excluded portions of the other overall measurement planes as shown in the figures below. In addition to the measurements on these 2mm- and 5mm-spaced planes, each module is measured in an entire plane at 70 mm spacing in its broadside direction, demonstrating compliance at a conservative distance representing the non-detect threshold distance of the proximity detector. 4

Figure 5.2.4.1 Measurement planes for Module 0. 5

Figure 5.2.4.2 Measurement planes for Module 1. 6

Figure 5.2.4.3 Measurement planes for Module 2. 7

Figure 5.2.4.4 Measurement planes for Module 3. 8

Simulation Models In the following group of figures, the detailed simulation models employed for each module’s analysis are illustrated. Figure 6.3.4-1: 3D model used for Module 0 (Right Array), the antenna array is highlighted Figure 6.3.4-2: 3D model used for Module 1 (Left Array), the antenna array is highlighted 9

Figure 6.3.4-3: 3D model used for Module 2 (Front Array), the antenna array is highlighted Figure 6.3.4-4: 3D model used for Module 3 (Back Array), the antenna array is highlighted . 10

3. Appendix B: Detailed Strategy for Finding Worst Case Beams More details of finding the worst-case near field results are described below: Full-power beams are beams in which all four antenna array elements are excited with the full available power from their respective PAs. The simulations excluded those few beams that are not full-power; these are beams where less than all four (generally only one or two) of the antenna array elements are excited. Since the PA power per antenna port is limited to the same nominal value regardless of how many ports/elements are excited, these beams have substantially lower total power and hence lower emissions. Typically, excluding these beams with fewer than four elements excited results in around 9 beam pairs per module instead of 15. The detailed step-by-step process to accomplish this search is as follows: 1. For each full-power beam pair for each module, simulate in HFSS that beam pair’s power density at each x-y-z point in each of the reduced measurement planes for that module (i.e. the planes defined in Figures 5.2.4 for the modules, which exclude those regions which are within the proximity detector system’s effective region of operation for the module in question). a. The phase weights applied to each antenna element’s port for the simulation of each beam pair are taken from the codebook defined in the modem, wherein the beam pair was originally defined at design time. b. The magnitude weights applied to each antenna element’s port for the simulation of each individual beam comprising the beam pair are back-calculated from the measured EiRP pattern of that beam. This is necessary because there is no means to perform a conducted power measurement of these port powers on the module. The only means to perform an amplitude normalization of the simulated result is via normalization to the measured EiRP pattern. Essentially, this step calibrates the amplitude of the power applied in the simulation such that the simulated far-field EiRP is forced to correspond to the measured one. 2. For each of the reduced measurement planes for each module, identify from Step 1 the beam pair having the worst-case power density in that plane. 3. Measure the power density in each of the reduced measurement planes for each module, for the respective worst-case beam pair identified via simulation in Step 21. 4. ​ easurement plane defined around the device (for example, the entire measurement For each ​overall m plane at 5 mm spacing from the “back” side of the device), considering all of the results from Step 3 for reduced measurement planes that fall within that ​overall m ​ easurement plane, select the highest ​ easurement plane. power density value. This is the worst-case power density for that ​overall m 5. Considering all of the ​overall ​measurement planes comprising a use condition (for example, body-worn accessory condition is comprised of the planes 5 mm from the front and rear surfaces of the device), select for those planes the worst-case power density value found in Step 4. This is the reported power density value for the use case in question. The above steps are repeated for each of the two mm-wave frequency bands (n261 and n260, i.e. 28 GHz and 39 GHz) that the device supports. One exception to the above process is for the selection of worst case beam pair at 70 mm distance (i.e. at the conservative transition distance of sensor’s detect/undetect distance). For the 70 mm distance, we use the measured EIRP and pick the highest EIRP beam pair and the beam pair with highest total radiated power to do the power density measurements. 1 In practice, for most module/plane combinations, the worst two or three beam pairs were measured (rather than only one), particularly when simulated PD results for the worst beam pairs were close in values, e.g. comparable to measurement tolerance, and of significant magnitude. In this way, the search outcomes were made more conservative. 11

4. Appendix B1: Port Excitations in HFSS The encrypted array module has the predefined 8 ports for horizontal and vertical feed excitations. These ports are shown in Figure 7.1.1-1 below. The locations of these ports can not be modified by the OEM. Although it is not possible to display the internal feeding structure of the module in the figure below, a representation of the locations of all eight feed points on the antennas is provided in the Operational Description document. The excitation magnitudes and phases for these ports can be loaded from a csv file using the “Edit Sources” option in HFSS. An example of the edited sources (loaded magnitudes & phases) is shown in Figure 7.1.1-2. Note that since HFSS is a frequency-domain finite element method solver, the excitation waveform can be considered as sinusoidal. Figure 7.1.1-1: All 8 ports and the highlighted H1 port (Horizontal) in HFSS. 12

Figure 7.1.1-2: Magnitudes and phases of a beam pair are loaded in HFSS. 13

5. Appendix B2: Material Properties in HFSS Figure 8.1.1-1: Parts/materials near an array module (Module 0). Parts Material Dielectric Loss Conductivity Constant Tangent (S/m) Housing of Mod, Array Housing, Liner Plastic 2.7 0.007 Adhesive Adhesive 3.2 0.04 Glass Inlay Glass 7.3 0.015 PCB (FR4) FR4 3.5 0.02 Housing of phone, Battery Aluminum 33000000 PCB (Cu), Heat Spreader, 4G LTE Copper 40000000 Antenna Table 5.1.1-1 Parts and material properties around Module 0. 14

6. Appendix C: Power Density and EiRP Results Power Density Simulated and Measured Results The simulated average power density at 38.5 GHz for all the beampairs in each of the modules is in the tables below: Simulated Simulated Simulated Simulated N260 (38.5 GHz) Avg Pd Avg Pd Avg Pd Avg Pd Module 0 (Right Array) (W/m²) (W/m²) (W/m²) (W/m²) Beam Left Bottom Back Front # Pair Ant Group @5 mm @5 mm @5 mm @2 mm 1 29-161 AG0 + AG1 0.11 0.27 3.55 1.07 2 30-160 AG0 + AG1 0.09 0.32 4.19 1.53 3 31-159 AG0 + AG1 0.13 0.62 3.99 1.07 4 32-158 AG0 + AG1 0.12 0.56 4.32 0.89 5 33-157 AG0 + AG1 0.11 0.27 3.25 1.33 6 48-179 AG0 + AG1 0.08 0.25 3.85 1.51 7 49-177 AG0 + AG1 0.10 0.14 3.11 1.20 8 50-178 AG0 + AG1 0.10 0.42 3.77 1.59 9 51-176 AG0 + AG1 0.15 0.58 4.02 0.79 10 1-129 AG0 + AG1 11 7-135 AG0 + AG1 The simulations excluded these beams that are not full-power; these are beams where less than all four (generally only one or two) of the 12 8-136 AG0 + AG1 antenna array elements are excited. Since the PA power per antenna port is limited to the same nominal value regardless of how many 13 9-137 AG0 + AG1 ports/elements are excited, these beams have substantially lower 14 18-146 AG0 + AG1 total power and hence lower emissions. Typically, excluding these beams with fewer than four elements excited results in the above 9 15 19-147 AG0 + AG1 beam pairs per module instead of 15. Table 6.3.5-1 Simulated avg. power density data at ​38.5 GHz​ for ​Module 0​ (Right Array). 15

Simulated Simulated Simulated Simulated N260 (38.5 GHz) Avg Pd Avg Pd Avg Pd Avg Pd Module 1 (Left Array) (W/m²) (W/m²) (W/m²) (W/m²) Beam Right Top Back Front # Pair Ant Group @5 mm @5 mm @5 mm @2 mm 1 24-152 AG0 + AG1 0.10 0.48 4.39 0.79 2 25-153 AG0 + AG1 0.08 0.08 3.62 1.46 3 26-154 AG0 + AG1 0.11 0.53 2.98 0.98 4 27-156 AG0 + AG1 0.25 0.28 4.74 1.46 5 28-155 AG0 + AG1 0.10 0.53 3.87 1.25 6 44-173 AG0 + AG1 0.11 0.19 4.10 1.23 7 45-172 AG0 + AG1 0.13 0.11 2.44 1.09 8 46-174 AG0 + AG1 0.10 0.33 3.84 1.75 9 47-175 AG0 + AG1 0.11 0.62 3.77 0.95 10 0-128 AG0 + AG1 11 4-133 AG0 + AG1 The simulations excluded these beams that are not full-power; these are beams where less than all four (generally only one or two) of the 12 5-132 AG0 + AG1 antenna array elements are excited. Since the PA power per antenna port is limited to the same nominal value regardless of how many 13 6-134 AG0 + AG1 ports/elements are excited, these beams have substantially lower 14 16-144 AG0 + AG1 total power and hence lower emissions. Typically, excluding these beams with fewer than four elements excited results in the above 9 15 17-145 AG0 + AG1 beam pairs per module instead of 15. Table 6.3.5-2 Simulated avg. power density data at ​38.5 GHz​ for ​Module 1​ (Left Array). 16

Simulated Simulated Simulated Simulated Simulated N260 (38.5 GHz) Avg Pd Avg Pd Avg Pd Avg Pd Avg Pd Module 2 (Front Array) (W/m²) (W/m²) (W/m²) (W/m²) (W/m²) Beam Top Back Left Right Front # Pair Ant Group @5 mm @ 5 mm @5 mm @5 mm @5 mm 1 39-168 AG0 + AG1 3.63 2.66 2.99 0.35 2.45 2 40-167 AG0 + AG1 4.16 2.91 1.94 0.14 2.56 3 41-171 AG0 + AG1 4.04 2.49 1.27 0.39 3.11 4 42-170 AG0 + AG1 3.56 2.67 1.31 0.36 2.38 5 43-169 AG0 + AG1 3.84 2.40 1.76 0.14 3.07 6 56-185 AG0 + AG1 3.92 2.70 1.72 0.45 2.71 7 57-184 AG0 + AG1 4.92 2.85 2.53 0.08 2.22 8 58-186 AG0 + AG1 5.13 3.65 0.64 0.16 2.97 9 59-187 AG0 + AG1 4.85 3.99 1.91 0.47 2.23 10 3-131 AG0 + AG1 The simulations excluded these beams that are not full-power; these are 11 13-142 AG0 + AG1 beams where less than all four (generally only one or two) of the antenna 12 14-141 AG0 + AG1 array elements are excited. Since the PA power per antenna port is limited to the same nominal value regardless of how many ports/elements are excited, 13 15-143 AG0 + AG1 these beams have substantially lower total power and hence lower emissions. Typically, excluding these beams with fewer than four elements 14 22-150 AG0 + AG1 excited results in the above 9 beam pairs per module instead of 15. 15 23-151 AG0 + AG1 Table 6.3.5-3 Simulated avg. power density data at ​38.5 GHz​ for ​Module 2​ (Front Array). 17

Simulated Simulated Simulated Simulated N260 (38.5 GHz) Avg Pd Avg Pd Avg Pd Avg Pd Module 3 (Back Array) (W/m²) (W/m²) (W/m²) (W/m²) Beam Right Left Top Front # Pair Ant Group @ 5 mm @5 mm @5 mm @2 mm 1 34-163 AG0 + AG1 0.59 0.89 1.32 0.90 2 35-162 AG0 + AG1 0.68 1.02 2.03 0.66 3 36-165 AG0 + AG1 0.57 0.84 1.78 0.77 4 37-166 AG0 + AG1 0.61 1.28 1.69 0.60 5 38-164 AG0 + AG1 0.58 0.79 1.33 0.68 6 52-180 AG0 + AG1 0.81 1.08 2.01 1.08 7 53-182 AG0 + AG1 0.58 0.84 1.07 0.36 8 54-183 AG0 + AG1 0.61 0.37 1.52 0.87 9 55-181 AG0 + AG1 0.57 0.65 1.38 0.94 10 2-130 AG0 + AG1 11 10-140 AG0 + AG1 The simulations excluded these beams that are not full-power; these are beams where less than all four (generally only one or two) of the 12 11-139 AG0 + AG1 antenna array elements are excited. Since the PA power per antenna port is limited to the same nominal value regardless of how many 13 12-138 AG0 + AG1 ports/elements are excited, these beams have substantially lower 14 20-148 AG0 + AG1 total power and hence lower emissions. Typically, excluding these beams with fewer than four elements excited results in the above 9 15 21-149 AG0 + AG1 beam pairs per module instead of 15. Table 6.3.5-4 Simulated avg. power density data at ​38.5 GHz​ for ​Module 3​ (Back Array). 18

A comparison between the simulated and measured average power density for the worst beam pair of each surface is tabulated below. The worst beam pair here refers to the measured worst beam pair at each surface for each module. Measured Simulated Avg. Avg. Beam Beam Exposure Test Test Config PD (W/m²) PD (W/m²) ID 1 ID 2 Conditions separation avg. area: avg. area: 4 cm² 4 cm² 30 160 Front Surface 2 mm 0.49 1.53 Module 0 32 158 Back Surface 5 mm 4.28 4.32 (Right Array) Freq: 38.5 GHz 51 176 Left Surface 5 mm 0.38 0.15 31 159 Bottom Surface 5 mm 0.43 0.62 Table 6.3.5-9 Simulated and measured avg. power density data for Module 0 (Right Array). Measured Simulated Avg. Avg. Beam Beam Exposure Test Test Config PD (W/m²) PD (W/m²) ID 1 ID 2 Conditions separation avg. area: avg. area: 4 cm² 4 cm² 46 174 Front Surface 2 mm 0.55 1.75 Module 1 27 156 Back Surface 5 mm 4.17 4.74 (Left Array) Freq: 38.5 GHz 27 156 Right Surface 5 mm 0.19 0.25 47 175 Top Surface 5 mm 0.27 0.62 Table 6.3.5-10 Simulated and measured avg. power density data for Module 1 (Left Array). Measured Simulated Avg. Avg. Beam Beam Exposure Test Test Config PD (W/m²) PD (W/m²) ID 1 ID 2 Conditions separation avg. area: avg. area: 4 cm² 4 cm² 59 187 Back Surface 5 mm 2.55 3.99 Module 2 59 187 Right Surface 5 mm 0.727 0.47 (Front Array) 39 168 Left Surface 5 mm 3.01 2.99 Freq: 38.5 GHz 59 187 Top Surface 5 mm 5.2 4.85 41 171 Front Surface 5 mm 1.63 3.11 Table 6.3.5-11 Simulated and measured avg. power density data for Module 2 (Front Array). 19

Measured Simulated Avg. Avg. Beam Beam Exposure Test Test Config PD (W/m²) PD (W/m²) ID 1 ID 2 Conditions separation avg. area: avg. area: 4 cm² 4 cm² 52 180 Front Surface 2 mm 0.68 1.08 Module 3 52 180 Right Surface 5 mm 0.67 0.81 (Back Array) Freq: 38.5 GHz 37 166 Left Surface 5 mm 0.93 1.28 52 180 Top Surface 5 mm 3.11 2.01 Table 6.3.5-12 Simulated and measured avg. power density data for Module 3 (Back Array). The measurement vs. simulation agreement for power density is very good. In 12 of the 17 cases presented, the disagreement is 2 dB or less. The remaining five cases, where the delta exceeds 2 dB, are cases where the power density value is insignificant (low relative the limit, in fact < 1.6 W/m^2 in all of these cases). Furthermore, in all cases with the highest power density values (values of 4 W/m^2 or greater, which determine the compliance level of the device), the agreement is within 0.6 dB. The increased delta for the very low field value regions is speculated to be due to the combined impacts of uncertainty in the measurement and less mesh refinement in the simulation (in these areas of lower energy). In any case, the validity of the simulation for rank-ordering the beam pairs is well demonstrated. Measured EiRP Results The table 7.1 below summarizes the EIRP of all beam pairs measured in Motorola’s development labs utilizing Keysight CATR (Compact Antenna Test Range) Model 230. This testing is done at NR - ARFCN ​2254166​, Frequency: 38500.02 MHz for the 100 MHz Bandwidth with 66 RB starting @0 for QPSK CP-OFDM Modulation. The highlighted rows correspond to beampairs with maximum EIRP for each of the modules and are used to determine the beampair for PD measurement at 70 mm distance (threshold of sensor detection distance) in the principal plane direction for each module. Note that these EiRP data are measured in a different test environment than are the official reported EiRP results measured at Sporton’s lab for Part 2/Part 30 compliance. It can be expected that these results will differ from each other. The results presented in this section are non-official and are not reported for Part 2/Part 30 compliance. They are presented here because they are representative of the results used in the worst-case-beam selection process as described in this appendix and the accompanying reports. 20

Antenna EIRP Total Module Beam ID1 Beam ID2 (dBm) 0 31 159 21.9 0 49 177 21.44 0 51 176 20.71 0 50 178 20.67 0 32 158 20.46 0 48 179 19.69 0 33 157 19.16 0 18 146 18.81 0 30 160 18.57 0 29 161 18.04 0 8 136 17.52 0 7 135 16.73 0 19 147 16.67 0 9 137 16.01 0 1 129 13.96 1 45 172 21.96 1 47 175 21.3 1 27 156 21.18 1 44 173 21.09 1 46 174 20.36 1 26 154 20.33 1 25 153 20.17 1 28 155 20.12 1 24 152 19.27 1 4 133 18.72 1 6 134 17.9 1 5 132 17.71 1 17 145 17.62 1 16 144 17.58 1 0 128 13.36 21

2 59 187 21.71 2 56 185 21.59 2 43 169 21.51 2 58 186 21.47 2 57 184 20.86 2 42 170 20.67 2 39 168 20.57 2 40 167 20.22 2 41 171 18.88 2 23 151 18.03 2 15 143 17.83 2 14 141 17.04 2 22 150 16.86 2 13 142 16.51 2 3 131 12.81 3 53 182 23.11 3 52 180 22.83 3 55 181 22.67 3 36 165 22.57 3 38 164 21.88 3 37 166 20.94 3 34 163 20.9 3 35 162 20.84 3 54 183 20.73 3 20 148 18.85 3 21 149 18.34 3 11 139 17.82 3 12 138 17.44 3 10 140 16.84 3 2 130 13.09 Table 7.1 Measured EIRP for all beampairs 22


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Document Modified: 2019-03-23 15:01:07
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