FCC 47 CFR MPE REPORT
FCC ID: WLQAM9521RX
Product Information
Brand: Polk Audio
Product: Polk DSB Soundbar System
Model Number: DSB2 WIRELESS SUBWOOFER
FCC ID: WLQAM9521RX
Preparation Details
Prepared for: Polk Audio
Address: 5601 Metro Drive, Baltimore, Maryland, United States, 21215
Prepared By: EST Technology Co., Ltd.
Address: Santun(guantai Road), Houjie Town, DongGuan City, GuangDong, China.
Contact: Tel: 86-769-83081888-808
Report Number: ESTE-R1605078
Date of Test: May 23 ~ 29, 2016
Date of Report: May 31, 2016
Maximum Permissible Exposure
1. Applicable Standard
Systems operating under the provisions of this section shall be operated in a manner that ensures that the public is not exposed to radio frequency energy level in excess limit for maximum permissible exposure. In accordance with 47 CFR FCC Part 2 Subpart J, section 2.1091 this device has been defined as a mobile device whereby a distance of 0.2m normally can be maintained between the user and the device.
(a) Limits for Occupational / Controlled Exposure
| Frequency Range (MHz) | Electric Field Strength E) (V/m) | Magnetic Field Strength (H) (A/m) | Power Density (S) (mW/cm2) | Averaging Times | E | 2, | H | 2 or S (minutes) |
|---|---|---|---|---|
| 0.3-3.0 | 614 | 1.63 | (100)* | 6 |
| 3.0-30 | 1842/f | 4.89/f | (900/f)* | 6 |
| 30-300 | 61.4 | 0.163 | 1.0 | 6 |
| 300-1500 | F/300 | 6 | ||
| 1500-10000 | 5 | 6 |
(b) Limits for General Population / Uncontrolled Exposure
| Frequency Range (MHz) | Electric Field Strength E) (V/m) | Magnetic Field Strength (H) (A/m) | Power Density (S) (mW/cm2) | Averaging Times | E | 2, | H | 2 or S (minutes) |
|---|---|---|---|---|
| 0.3-1.34 | 614 | 1.63 | (100)* | 30 |
| 1.34-30 | 824/f | 2.19/f | (180/f)* | 30 |
| 30-300 | 27.5 | 0.073 | 0.2 | 30 |
| 300-1500 | F/1500 | 30 | ||
| 1500-10000 | 1.0 | 30 |
Note: f=frequency in MHz; *Plane-wave equivalent power density
2. MPE Calculation Method
The formulas for calculating Electric Field Strength (E) and Power Density (Pd) are provided:
- E (V/m) = (30*P*G)0.5/d
- Power Density: Pd (W/m2) = E2/377
Where:
- E = Electric Field (V/m)
- P = Peak RF output Power (W)
- G = EUT Antenna numeric gain (numeric)
- d = Separation distance between radiator and human body (m)
The formula for Power Density can also be expressed as:
Pd = (30*P*G) / (377*d2)
From the peak EUT RF output power, the minimum mobile separation distance (d=0.2m), and the gain of the used antenna, the RF power density can be obtained.
3. Calculated Result and Limit
| Mode | Frequency (MHz) | Peak output power (dBm) | Peak output power (mW) | Target power (dBm) | Antenna gain (dBi) | Antenna gain (Linear) | Power Density (S) (mW/cm2) | Limited Power Density (S) (mW/cm2) | Test Result |
|---|---|---|---|---|---|---|---|---|---|
| GFSK | 2402 | 0.825 | 1.209 | -1±2 | 0 | 1 | 0.00025 | 1 | Compiles |
| GFSK | 2441 | 0.869 | 1.222 | -1±2 | 0 | 1 | 0.00025 | 1 | Compiles |
| GFSK | 2480 | -0.081 | 0.982 | -1±2 | 0 | 1 | 0.00025 | 1 | Compiles |
| 8-DPSK | 2402 | 0.323 | 1.077 | -1±2 | 0 | 1 | 0.00025 | 1 | Compiles |
| 8-DPSK | 2441 | 0.367 | 1.088 | -1±2 | 0 | 1 | 0.00025 | 1 | Compiles |
| 8-DPSK | 2480 | -0.550 | 0.881 | -1±2 | 0 | 1 | 0.00025 | 1 | Compiles |
