SAR Test Report for BAOFENG P52UV Two-Way Radio

Summary

Statement of Compliance

This device complies with Specific Absorption Rate (SAR) limits for general population/uncontrolled exposure (1.6 W/kg) as specified in FCC 47 CFR part 2 (2.1093) and ANSI/IEEE C95.1-1992. Testing was conducted according to IEEE 1528-2013 and FCC KDB publications.

Test Standards and Report Version

Test Standards

Tests were performed according to:

• FCC 47 Part 2.1093: Radiofrequency Radiation Exposure Evaluation: Portable Devices
• IEEE Std C95.1, 1999 Edition: IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz
• IEEE Std 1528M-2013: IEEE Recommended Practice for Determining the Peak Spatial-Average Specific Absorption Rate (SAR) in the Human Head from Wireless Communications Devices: Measurement Techniques.

FCC published RF exposure KDB procedures were also followed, including KDB 865664 D01, KDB 865664 D02, and KDB 447498 D01.

Report Version

Product Description

Client Information

Applicant, Manufacturer, and Factory: PO FUNG ELECTRONIC(HK) INTERNATIOANL GROUP COMPANY
Address: 3/F FULOK BLDG 131-133 WING LOK ST SHEUNG WAN, Hong Kong

Main Unit Details

Radio Specification Description

Remarks:

1. The EUT battery must be fully charged and checked periodically during the test to ascertain uniform power.
2. The maximum duty cycle supported by the device is 50%.
3. Model difference statement: only model & front shell design are different.

Testing Laboratory Information

Laboratory Details

Laboratory Name: Shenzhen Huatongwei International Inspection Co., Ltd.
Laboratory Location: 1/F, Bldg 3, Hongfa Hi-tech Industrial Park, Genyu Road, Tianliao, Gongming, Shenzhen, China
Connect information: Tel: 86-755-26715499, E-mail: cs@szhtw.com.cn, Website: http://www.szhtw.com.cn
Qualifications: FCC, Accreditation Number: 762235

Environmental Conditions

During measurements, environmental conditions were within the listed ranges:

• Ambient temperature: 18 °C to 25 °C
• Ambient humidity: 30%RH to 70%RH
• Air Pressure: 950-1050mbar

Equipments Used during the Test

A comprehensive list of test equipment, including Data Acquisition Electronics (DAE), E-field Probes, Universal Radio Communication Testers, Dielectric Assessment Kits, Network Analyzers, System Validation Antennas, System Validation Dipoles, Signal Generators, Power Viewers, Power Sensors, Power Amplifiers, Dual Directional Couplers, and Attenuators, was used. Calibration dates and due dates are detailed in the full report. All dipoles were not physically damaged or repaired during the interval.

Measurement Uncertainty

Per KDB 865664 D01 SAR Measurement 100 MHz to 6 GHz, when the highest measured 1-g SAR within a frequency band is < 1.5 W/kg, the expanded SAR measurement uncertainty must be ≤ 30% for a confidence interval of k = 2. These conditions were met, therefore extensive SAR measurement uncertainty analysis described in IEEE Std 1528-2013 was not required.

SAR Measurements System Configuration

SAR Measurement Set-up

The DASY5 system for compliance tests includes:

• A standard high precision 6-axis robot (Stäubli RX family) with controller and software, and an arm extension for data acquisition electronics (DAE).
• A dosimetric probe (isotropic E-field probe) optimized and calibrated for tissue simulating liquid, equipped with an optical surface detector system.
• A data acquisition electronic (DAE) for signal amplification, multiplexing, AD-conversion, offset measurements, mechanical surface detection, and collision detection.
• A unit to operate the optical surface detector.
• An Electro-Optical Coupler (EOC) for converting optical signals to digital electric signals.
• The DASY5 measurement server for real-time data evaluation, robot control, and safety operation, running on Windows 2003.
• DASY5 software and SEMCAD data evaluation software.
• Remote control with teach panel and additional robot safety circuitry.
• A generic twin phantom for left-hand and right-hand usage testing.
• A device holder for handheld Mobile Phones.
• Tissue simulating liquid mixed according to specified recipes.
• System validation dipoles for verifying system functionality.

A system diagram illustrates the connections between the robot controller, measurement server, DAE, E-field probe, phantom, and other components.

DASY5 E-field Probe System

SAR measurements were conducted with the dosimetric probe EX3DV4 (manufactured by SPEAG), designed in a triangular configuration and optimized for dosimetric evaluation.

Probe Specification

• Construction: Symmetrical design with triangular core, interleaved sensors, built-in shielding against static charges, PEEK enclosure material.
• Calibration: ISO/IEC 17025 calibration service available.
• Frequency: 10 MHz to 10 GHz; Linearity: ± 0.2 dB (30 MHz to 10 GHz).
• Directivity: ±0.1 dB in TSL (rotation around probe axis), ±0.3 dB in TSL (rotation normal to probe axis).
• Dynamic Range: 10 µW/g to > 100 mW/g; Linearity: ± 0.2 dB.
• Dimensions: Overall length: 337 mm (Tip: 20 mm), Tip diameter: 2.5 mm (Body: 12 mm), Distance from probe tip to dipole centers: 2.0 mm.
• Application: General dosimetry up to 10 GHz, dosimetry in strong gradient fields, compliance tests of Mobile Phones.
• Compatibility: DASY3, DASY4, DASY52 SAR and higher, EASY4/MRI.

An illustration shows the triangular sensor arrangement of the dipole sensor with high-resistance lines, detector diodes, and Δ-BEAM and I-BEAM configurations.

Phantoms

The ELI4 Phantom is used for compliance testing of handheld and body-mounted wireless devices (30 MHz to 6 GHz). It is fully compatible with standards and tissue-simulating liquids, optimized for performance, and integrated into standard phantom tables. A cover prevents liquid evaporation. Reference markings allow complete setup installation by teaching three points. The phantom is compatible with all SPEAG dosimetric probes and dipoles.

Device Holder

The DASY device holder, supplied by SPEAG, is designed to accommodate various positions specified in the standard. It features two scales for device rotation (body axis) and inclination (ear reference points), ensuring no repositioning is needed when changing angles.

SAR Test Procedure

Scanning Procedure

The SAR test procedure involves four main steps:

1. Step 1: Power Reference Measurement: Monitors the power drift of the device under test by measuring local SAR at a point within 8 mm of the phantom inner surface closest to the DUT.
2. Step 2: Area Scan: A fast, two-dimensional scan to locate high field values. Sophisticated interpolation routines find maximum locations even on coarse grids. The field maximal found within a specified dB range (e.g., 2 dB for IEEE 1528/IEC 62209, 3 dB for ARIB) is computed.
3. Step 3: Zoom Scan: Used to assess peak spatial SAR values within a cubic averaging volume (1g and 10g of simulated tissue). Points are measured within a cube centered on the maxima from the Area Scan. The averaged SAR values for 1g and 10g are evaluated. Resolutions for Area Scan and Zoom Scan are specified based on frequency bands and device dimensions, ensuring adequate measurement points.
4. Step 4: Power Drift Measurement: Measures the field at the same location as the most recent power reference measurement to monitor power drift of the device under test within a batch process. SAR drift must be kept within ± 5%.

Data Storage and Evaluation

Data Storage

DASY5 software stores acquired data (microvolt readings from probe sensors) and necessary software parameters (probe calibration, liquid parameters, device frequency, modulation data) in '.DA4' measurement files. This allows verification of the setup and correction of incorrect parameter settings post-measurement.

Data Evaluation

SEMCAD software automatically calculates field units from microvolt readings. Parameters like probe sensitivity (Normi, ai0, ai1, ai2), conversion factor (ConvFi), diode compression point (Dcpi), device frequency (f), crest factor (cf), conductivity (σ), and density (ρ) are used. These parameters are crucial for accurate evaluation, including linearization of the filtered input signal to account for detector diode compression characteristics and compensation for peak power in pulsed fields. Formulas are applied to evaluate compensated input signals into primary field data (electric and magnetic field strengths).

Position of the Wireless Device in Relation to the Phantom

Front-of-face

For front-of-face devices like two-way radios, the device is held at a specified distance (25 mm if not otherwise stated by the manufacturer) from the phantom surface during transmission. A diagram illustrates a two-way radio positioned with a 25mm separation from a flat phantom.

Body Position

For body-worn devices (e.g., mobile phones, PDAs), the device transmits while mounted on a person's body using an approved carry accessory. A diagram illustrates a device positioned touching a flat phantom for body-worn testing.

Dielectric Property Measurements & System Check

Tissue Dielectric Parameters

The temperature of the tissue-equivalent medium must be 18°C to 25°C, and within ± 2°C of the characterization temperature. Dielectric parameters (permittivity εr and conductivity σ) must be measured before SAR measurements and re-measured every 3-4 days or if out of tolerance. For SAR systems with error compensation, a ± 10% tolerance for εr and σ is allowed for frequencies ≤ 3 GHz. For Head tissue simulating liquid at 450 MHz, target εr is 43.5 and σ is 0.87 S/m. Measured values on 2021-01-08 were εr 44.54 (2.39% delta) and σ 0.897 S/m (3.13% delta), both within ±5% limit at 22.1°C.

SAR System Validation

SAR system validation confirms measurement accuracy. The SAR systems, probes, and software versions were validated against performance specifications using reference dipoles with tissue-equivalent media. Probe calibrations are frequency-dependent. A summary table details validation status, including dates, frequencies, SAR probes, and tissue dielectric parameters, confirming all checks passed.

System Check

SAR system verification is performed for each frequency band and probe calibration point to confirm measurement accuracy. Measurements were conducted in the flat section of the TWIN SAM or ELI phantom (shell thickness 2.0±0.2 mm) filled with Body or Head simulating liquid (depth ≥ 15.0 cm for ≤ 3 GHz, ≥ 10.0 cm for > 3 GHz). The DASY system with an E-Field Probe was used. The dipole was mounted on a tripod with its feed point below the phantom center, oriented parallel to the body axis. Standard measuring distances were 10 mm (above 1 GHz) and 15 mm (below 1 GHz) from dipole center to liquid surface. Coarse and fine grids were aligned with the dipole. Results are normalized to 1 W input power. A system performance check setup diagram illustrates the signal generator, amplifier, directional coupler, attenuators, and the probe/phantom/dipole arrangement.

For Head 450MHz, a system check with 250mW input power yielded SAR(1g) of 1.19 W/kg (normalized to 1W: 4.76 W/kg) and SAR(10g) of 0.792 W/kg (normalized to 1W: 3.17 W/kg), showing deltas of 6.25% (1g) and 5.60% (10g) respectively, which are within the ±10% limit.

SAR Exposure Limits

SAR assessments align with FCC 47 CFR § 2.1093 requirements.

Population/Uncontrolled Environments: Locations where individuals have no knowledge or control of their exposure.

Occupational/Controlled Environments: Locations where exposure may be incurred by people aware of potential exposure (e.g., due to employment).

Radiated Power Measurement Results

The following table summarizes the radiated power measurement results for GMRS mode:

Maximum Tune-up Limit

SAR values were scaled to the maximum allowed power to determine compliance per KDB publication 447498 D01.

SAR Measurement Results

The SAR evaluation was performed for both front-of-face and body-worn positions. The distance for front-of-face tests was 25mm, and for body-worn tests, it was 0mm. Batteries were fully charged before measurements. The body-worn SAR evaluation used a Leather Case accessory attached to the DUT, touching the planar phantom's outer surface.

Front-of-face SAR Results

Highest reported SAR (1g) for front-of-face was 1.595 W/kg (CH4, 462.6375 MHz).

Body-worn SAR Results

Highest reported SAR (1g) for body-worn was 1.589 W/kg (CH4, 462.6375 MHz).

Detailed SAR Test Data Plots are available in Appendix A of the full report.

Test Setup Photos

Photos illustrate the test setup, including the liquid depth in the ELI Phantom, the front-of-face setup with 25mm separation, and the body-worn setup with 0mm separation.

External Photos of the EUT

Various external views of the Equipment Under Test (EUT), the two-way radio, and its accessories are provided, showing different angles and dimensions with measurement scales.