Test Report

Applicant Information

Applicant: Ugreen Group Limited

Address: URGEEN Building, Longcheng Industrial Park, Longguanxi Road, Longhua, ShenZhen, China

Equipment Type: Bluetooth Audio Receiver/Transmitter

Model Name: CM403

Brand Name: UGREEN

FCC ID: 2AQI5-80893

Test Standard: 47 CFR Part 15 Subpart C (refer to section 3.1)

Sample Arrival Date: Oct. 25, 2024

Test Date: Oct. 25, 2024 - Jan. 16, 2025

Date of Issue: Apr. 24, 2025

Issued By

Shenzhen BALUN Technology Co., Ltd.

Tested by: Julie Zhu

Checked by: Ye Hongji

Approved by: Sunny Zou (Technical Director)

Revision History

General Information

1.1 Test Laboratory

Name: Shenzhen BALUN Technology Co., Ltd.

Address: Block B, 1/F, Baisha Science and Technology Park, Shahe Xi Road, Nanshan District, Shenzhen, Guangdong Province, P. R. China

Phone Number: +86 755 6685 0100

1.2 Test Location

Name: Shenzhen BALUN Technology Co., Ltd.

Location: Block B, 1/F, Baisha Science and Technology Park, Shahe Xi Road, Nanshan District, Shenzhen, Guangdong Province, P. R. China

Accreditation Certificate: The laboratory is a testing organization accredited by FCC as an accredited testing laboratory. The designation number is CN1196.

Product Information

2.1 Applicant Information

Applicant: Ugreen Group Limited

Address: UGREEN Building, Longcheng Industrial Park Longguanxi Road, Longhua, ShenZhen, China

2.2 Manufacturer Information

Manufacturer: Ugreen Group Limited

Address: UGREEN Building, Longcheng Industrial Park Longguanxi Road, Longhua, ShenZhen, China

2.3 Factory Information

Factory: Huizhou Zhize Technology Co., Ltd

Address: No.1, Nantang Road, Chenjiang Street, Zhongkai High-tech Zone, Huizhou City (Factory Building No.5)

2.4 General Description for Equipment under Test (EUT)

EUT Name: Bluetooth Audio Receiver/Transmitter

Model Name Under Test: CM403

Series Model Name: N/A

Description of Model name differentiation: N/A

Hardware Version: V1

Software Version: V0.5 (1008)

Dimensions (Approx.): N/A

Weight (Approx.): N/A

Remark: Product Number (P/N) code in the below table, for marketing purpose, will be marked on the marking plate.

Product Numbers: 80893, 80893EU, 80893UK, 80893US, 80893JP, 80893CN, 80893KC, 80893A, 80893B, 80893C, 80893P

2.5 Technical Information

Network and Wireless connectivity: Bluetooth (BR+EDR)

Modulation Technology: FHSS

Modulation Type: GFSK, π/4-DQPSK, 8-DPSK

Product Type: Mobile, Portable

Transfer Rate: DH5: 1 Mbps, 2DH5: 2 Mbps, 3DH5: 3 Mbps

Frequency Range: 2400 MHz to 2483.5 MHz

Number of Channel: 79 (at intervals of 1 MHz)

Tested Channel: 0 (2402 MHz), 39 (2441 MHz), 78 (2480 MHz)

Antenna Type: Chip Antenna

Antenna Gain: 2.5 dBi

Antenna Impedance: 50Ω

Antenna System (MIMO Smart Antenna): N/A

EUT Software Settings: Power level setup in software

Test Software Version: BT FCC Tool V2.24

Support Units (Software installation media): Notebook, Manufacturer: Lenovo, Model: X220

Mode Settings:

Run Software: The report includes a screenshot of the 'Actions BT FCC Tool V2.24' software interface, showing test parameters like RF Channel, Packet Type, TX Gain Index, and Access Code.

All channels listed: The document provides a table listing all 79 channels and their corresponding frequencies from 2402 MHz to 2480 MHz.

Summary of Test Results

3.1 Test Standards

The tests were conducted according to the following standards:

• 47 CFR Part 15, Subpart C: Intentional radiators of radio frequency equipment
• ANSI C63.10-2013: American National Standard for Testing Unlicensed Wireless Devices
• KDB 558074 D01 15.247 Meas Guidance v05r02: Guidance for compliance measurements on digital transmission system, frequency hopping spread spectrum system, and hybrid system devices operating under section 15.247 of the FCC rules

3.2 Test Verdict

The EUT passed all tested requirements:

General Test Configurations

4.1 Test Environments

During the measurement, the normal environmental conditions were within the listed ranges:

• Relative Humidity: 44% to 63%
• Atmospheric Pressure: 100 kPa to 102 kPa
• Temperature: NT (Normal Temperature) (+20.1°C to +23.9°C)
• Working Voltage of the EUT: NV (Normal Voltage) (3.7 V)

4.2 Test Equipment List

The following equipment was used for testing:

4.3 Test Software List

4.4 Measurement Uncertainty

The following measurement uncertainty levels have been estimated for tests performed on the EUT as specified in CISPR 16-4-2.

This uncertainty represents an expanded uncertainty expressed at approximately the 95% confidence level using a coverage factor of k=2.

Description of Test Setup

4.5.1 For Antenna Port Test

Conducted value (dBm) = Measurement value (dBm) + cable loss (dB)

For example: the measurement value is 10 dBm and the cable 0.5dBm used, then the final result of EUT: Conducted value (dBm) = 10 dBm + 0.5 dB = 10.5 dBm

Diagram 1 illustrates the test setup for antenna port measurements, showing connections between the EUT, Signal Generator, Vector Signal Generator, Display, Spectrum Analyzer, OSP, and PC.

4.5.2 For AC Power Supply Port Test

Diagram 2 depicts the test setup for AC power supply port testing, showing the EUT connected to a LISN, Pulse Limiter, Receiver, and Service Supplier, with a Communication Antenna.

4.5.3 For Radiated Test (Below 30 MHz)

Diagram 3 shows the radiated test setup for frequencies below 30 MHz, featuring the EUT within an anechoic chamber, connected to an EMI Receiver and an Antenna.

4.5.4 For Radiated Test (30 MHz-1 GHz)

Diagram 4 illustrates the radiated test setup for frequencies between 30 MHz and 1 GHz, showing the EUT, Antenna, EMI Receiver, and Preamplifier within an anechoic chamber.

4.5.5 For Radiated Test (Above 1 GHz)

Diagram 5 shows the radiated test setup for frequencies above 1 GHz, featuring the EUT, Antenna, Spectrum Analyzer, and Preamplifier within an anechoic chamber.

4.6 Measurement Results Explanation Example

4.6.1 For conducted test items:

The offset level in the spectrum analyzer is set to compensate for RF cable loss and the attenuator between the EUT's output port and the spectrum analyzer. This offset compensation ensures that the spectrum analyzer reading level accurately reflects the EUT's RF output level. The spectrum analyzer offset is calculated from the RF cable loss and the attenuator factor: Offset = RF cable loss + attenuator factor.

Test Items

5.1 Antenna Requirements

5.1.1 Relevant Standards

FCC §15.203 & 15.247(b) states that an intentional radiator must be designed to use only the antenna furnished by the responsible party. Permanently attached antennas or those with unique couplings are considered compliant. Standard antenna jacks or electrical connectors are prohibited for replacement by the user. This rule does not apply to carrier current devices or devices operated under specific sections (§ 15.211, § 15.213, § 15.217, § 15.219, or § 15.221), nor to radiators requiring professional installation or measurement at the installation site. The installer is responsible for ensuring the correct antenna is used to meet limits.

If directional gain exceeds 6 dBi, power must be reduced by the same amount in dB. For point-to-point operations, power is reduced by 1 dB for every 3 dB gain above 6 dBi. A permanently attached antenna or one with a unique coupling is sufficient for FCC compliance.

5.1.2 Antenna Anti-Replacement Construction

The antenna is embedded in the product, utilizing an embedded-in antenna design.

5.1.3 Antenna Gain

The antenna peak gain of the EUT is less than 6 dBi, so no reduction in maximum peak output power limit is necessary.

5.2 Frequency Hopping Systems

5.2.1 Relevant Standards

FCC §15.247(a) (1) (i) (ii) (iii) (iv); FCC §15.247(g); FCC §15.247(h) requirements for frequency hopping systems are detailed, including generation of hopping sequences, equal use of channels, receiver bandwidth matching, synchronization capabilities, and avoidance of coordination with other FHSS systems.

5.2.2 Description of the systems

1. The system operates with synchronous frequency changes across network stations, with periodic synchronization signaling from a primary station.
2. The hop set is designed to appear random in the near term and evenly distributed in the long term, with sequential hops randomly distributed in direction and magnitude.
3. Channels are categorized as used or unused, with a pseudo-random replacement of unused channels. All hopping channels are used equally on average.
4. The input and transmitted bandwidths are both 1 MHz. The receiver bandwidth matches the transmitted signal bandwidth.
5. Connected devices synchronize using a common clock and hopping sequence.
6. The EUT is not a short burst system.
7. The EUT cannot be coordinated with other FHSS systems.

5.3 Number of Hopping Frequencies

5.3.1 Limit

FCC §15.247(a) (1) (iii): Frequency hopping systems operating in the 2400 MHz to 2483.5 MHz bands must use at least 15 hopping frequencies.

5.3.2 Test Setup

Refer to section 4.5.1 for antenna port test setup description and ANNEX A for photos.

5.3.3 Test Procedure

The EUT's hopping function must be enabled. Spectrum analyzer settings include: Span set to the frequency band of operation, RBW set to less than 30% of channel spacing or 20 dB bandwidth (whichever is smaller), VBW ≥ RBW, Sweep set to auto, Detector function set to peak, and Trace set to max hold.

5.3.4 Test Result

Test Data:

Test Plots: The report includes spectrum analyzer plots demonstrating the number of hopping frequencies for GFSK and 8-DPSK modes across different frequency ranges.

5.4 Peak Output Power

5.4.1 Test Limit

FCC § 15.247(b): For frequency hopping systems in the 2400-2483.5 MHz band with at least 75 non-overlapping channels, the limit is 1 watt. For other systems in this band, the limit is 0.125 watts.

5.4.2 Test Setup

Refer to section 4.5.1 for antenna port test setup description and ANNEX A for photos.

5.4.3 Test Procedure

The module was tested in hopping-off mode. The lowest, middle, and highest channels were used to verify conducted RF output peak power. Spectrum analyzer settings included a Span of approximately 5 times the 20 dB bandwidth, RBW greater than the 20 dB bandwidth, VBW ≥ RBW, Sweep set to auto, Detector function set to peak, and Trace set to max hold.

5.4.4 Test Result

Peak Power Test Data:

Test Plots: Spectrum analyzer plots are provided for GFSK, π/4-DQPSK, and 8-DPSK modes at low, middle, and high channels, showing the peak output power measurements.

5.5 Occupied Bandwidth

5.5.1 Limit

FCC §15.247(a): Measurement of the 20dB bandwidth of the modulated signal.

5.5.2 Test Setup

Refer to section 4.5.1 for antenna port test setup description and ANNEX A for photos.

5.3.3 Test Procedure

Spectrum analyzer settings: Span approximately 2 to 5 times the 20 dB bandwidth, centered on a hopping channel. RBW in the range of 1% to 5% of the OBW. VBW ≥ RBW. Sweep set to auto. Detector function set to peak. Trace set to max hold. EUT transmits at maximum data rate.

5.5.4 Test Result

Test Data:

Test Plots: Spectrum analyzer plots are provided for 20 dB bandwidth measurements for GFSK, π/4-DQPSK, and 8-DPSK modes.

5.6 Carrier Frequency Separation

5.6.1 Limit

FCC §15.247(a): Hopping channel carrier frequencies must be separated by a minimum of 25 kHz or 2/3 of the 20 dB bandwidth of the hopping channel, whichever is greater.

5.6.2 Test Setup

Refer to section 4.5.1 for antenna port test setup description and ANNEX A for photos.

5.6.3 Test Procedure

The EUT's hopping function must be enabled. Spectrum analyzer settings: Span wide enough to capture peaks of two adjacent channels. RBW ≥ 1% of the span. VBW ≥ RBW. Sweep set to auto. Detector function set to peak. Trace set to max hold. Marker-delta function used to determine separation.

5.6.4 Test Result

Test Data:

Test Plots: Spectrum analyzer plots show the carrier frequency separation for GFSK and 8-DPSK modes.

5.7 Time of Occupancy (Dwell time)

5.7.1 Limit

FCC §15.247(a): For systems using at least 15 non-overlapping channels in the 2400-2483.5 MHz band, the average time of occupancy on any channel shall not exceed 0.4 seconds within a period of 0.4 seconds multiplied by the number of hopping channels. Systems may avoid or suppress transmissions on a particular frequency if at least 15 channels are used.

5.7.2 Test Setup

Refer to section 4.5.1 for antenna port test setup description and ANNEX A for photos.

5.7.3 Test Procedure

The EUT's hopping function must be enabled. Spectrum analyzer settings: Span set to zero, centered on a hopping channel. RBW ≤ channel spacing, and preferably RBW >> 1 / T (where T is expected dwell time). Sweep adjusted to capture dwell time. Video trigger and trigger delay may be used. Detector function: Peak. Trace: Max hold. Transmit time per hop (Pulse Time) is determined using marker-delta function. Calculations for Total of Dwell are provided.

5.7.4 Test Result

Test Data:

Test Plots: Spectrum analyzer plots show the pulse width and dwell time measurements for various modes.

5.8 Conducted Spurious Emission & Authorized-band band-edge

5.8.1 Limit

FCC §15.247(d): In any 100 kHz bandwidth outside the operating frequency band, the RF power must be at least 20 dB below the highest level within the band, based on conducted or radiated measurement.

5.8.2 Test Setup

Refer to section 4.5.1 for antenna port test setup description and ANNEX A for photos.

5.8.3 Test Procedure

Spectrum analyzer settings: Span wide enough to capture in-band and spurious emissions up to the 10th harmonic. RBW = 100 kHz, VBW = 300 kHz. Sweep set to auto. Detector function set to peak. Trace set to max hold.

5.8.4 Test Result

Test Data:

Hopping Mode Test Data:

Test Plots: Spectrum analyzer plots are provided for conducted spurious emissions and band edge measurements for GFSK and 8-DPSK modes.

Annex A: Test Setup Photos

The report references Annex A for test setup photos, including radiated test photos, conducted test photos, and conducted emission photos.

Annex B: EUT External Photos

The report references Annex B for EUT external photos.

Annex C: EUT Internal Photos

The report references Annex C for EUT internal photos.