FCC&IC TEST REPORT

1. GENERAL INFORMATION

1.1. GENERAL DESCRIPTION OF EUT

Product Name: FLOW 2-68 Triple Mode Low-Profile Mechanical Keyboard

Trade Mark: LOFREE

Test Model: OE928

Additional Model(s): /

Model Difference: /

Hardware Version: OE928-VIA-V1

Software Version: 1

Power Supply: DC 3.7V by battery(3000mAh) or DC from USB Port

EUT Supports Function: 2.4GHz ISM Bands: Bluetooth V5. 1

Test Sample(s) Number: AB25060084-01 (Engineer Sample)

Radio Specification Subject to this Report

• Bluetooth Version: Bluetooth LE
• Frequency Range: 2402MHz~2480MHz
• Modulation Type: GFSK
• Channel Spacing: 2MHz
• Channel Number(s): 40
• Antenna Type: PCB Antenna
• Antenna Gain: -0.58dBi(Max.)

1.2. DESCRIPTION OF SUPPORT EQUIPMENT

1.3. DESCRIPTION OF EXTERNAL I/O

1.4. GENERAL DESCRIPTION OF APPLIED STANDARDS

The tests were performed according to following standards:

• FCC Rules Part 15.247 - Frequency Hopping, Direct Spread Spectrum and Hybrid Systems that are in operation within the bands of 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.
• ANSI C63.10-2013 - American National Standard of Procedures for Compliance Testing of 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.
• RSS-Gen Issue 5 - General Requirements for Compliance of Radio Apparatus
• RSS-247 Issue 3 - Digital Transmission Systems (DTSs), Frequency Hopping Systems (FHSs) and Licence-Exempt Local Area Network (LE-LAN) Devices

1.5. DESCRIPTION OF TEST FACILITY

Test Lab: Aibo Standard Technology (Shenzhen) Co., Ltd.

Address: 101, Building B, Tuori New Energy Industrial Park, High-tech Park, Tianliao Community, Yutang Street, Guangming District, Shenzhen City, Guangdong Province, China

Tel: +(86) 0755 85250797

E-mail: Aibonorm@aibonorm.com

Website: www.Aibonorm.com

The test facility is recognized, certified, or accredited by the following organizations:

• A2LA-Lab Certificate No.: 7514.01
• Aibo Standard Technology (Shenzhen) Co., Ltd. has been accredited by A2LA for technical competence in the field of electrical testing, and proved to be in compliance with ISO/IEC 17025 General Requirements for the Competence of Testing and Calibration Laboratories and any additional program requirements in the identified field of testing.

FCC Accredited Lab.

• Designation Number: CN1411
• Test Firm Registration Number: 567066

ISED Wireless Device Testing Laboratories

• Company Number: 33924
• CAB identifier: CN0185

1.6. MEASUREMENT UNCERTAINTY

The measurement data show herein meets or exceeds the CISPR measurement uncertainty values specified in CISPR 16-4-2 and can be compared directly to specified limit to determine compliance.

Note: All measurement uncertainty values are shown with a coverage factor of k = 2 to indicate a 95 % level of confidence.

1.7. ENVIRONMENTAL CONDITIONS

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

1.8. DESCRIPTION OF TEST MODES

Operation Frequency List

For portable device, radiated emission was verified over X, Y, Z Axis, and shown the worst case in this report. The following operating modes were applied for the related test items. Pre-Scan has been conducted to determine the worst-case mode from all possible combinations between available modulations, data packets and antenna ports (if EUT with antenna diversity architecture), only the result of the worst case was recorded in the report.

List of Test Modes

Power setting during the test:

During testing, Channel & Power Controlling Software provided by the customer was used to control the operating channel as well as the output power level. The RF output power selection is for the setting of RF output power expected by the customer and is going to be fixed on the firmware of the final end product.

2. SUMMARY OF TEST RESULT

3. MEASUREMENT INSTRUMENTS LIST

Test Software

4. ANTENNA REQUIREMENT

1) Standard Requirement

15.203 requirement: An intentional radiator shall be designed to ensure that no antenna other than that furnished by the responsible party shall be used with the device. The use of a permanently attached antenna or of an antenna that uses a unique coupling to the intentional radiator, the manufacturer may design the unit so that a broken antenna can be replaced by the user, but the use of a standard antenna jack or electrical connector is prohibited.

15.247(b) (4) requirement: The conducted output power limit specified in paragraph (b) of this section is based on the use of antennas with directional gains that do not exceed 6dBi. Except as shown in paragraph (c) of this section, if transmitting antennas of directional gain greater than 6dBi are used, the conducted output power from the intentional radiator shall be reduced below the stated values in paragraphs (b)(1), (b)(2), and (b)(3) of this section, as appropriate, by the amount in dB that the directional gain of the antenna exceeds 6dBi.

2) Conclusion

Antenna in the interior of the equipment and no consideration of replacement. The gain of the antenna is -0.58dBi (Max.). It complies with the standard requirement.

5. CONDUCTED OUTPUT POWER

5.1. LIMIT

According to 15.247(b)(3) and IC RSS-247 5.4(d). For systems using digital modulation in the 902-928MHz, 2400-2483.5MHz, and 5725-5850MHz bands: 1 Watt. As an alternative to a peak power measurement, compliance with the 1 Watt limit can be based on a measurement of the maximum conducted output power. Maximum Conducted Output Power is defined as the total transmit power delivered to all antennas and antenna elements averaged across all symbols in the signaling alphabet when the transmitter is operating at its maximum power control level. Power must be summed across all antennas and antenna elements. The average must not include any time intervals during which the transmitter is off or is transmitting at a reduced power level. If multiple modes of operation are possible (e.g., alternative modulation methods), the maximum conducted output power is the highest total transmit power occurring in any mode.

5.2. TEST SETUP

Using a Spectrum Analyzer for Testing: Diagram shows a Spectrum Analyzer connected via RF cable to an EUT (Equipment Under Test).

Using a Broadband Power Meter for Testing: Diagram shows an EUT (Equipment Under Test) connected via RF cable to a Power Sensor, which is connected to a Broadband Power Meter.

5.3. TEST PROCEDURE

Using a Spectrum Analyzer for Testing: Remove the antenna from the EUT and then connect a low loss RF cable from the antenna port to the spectrum analyzer.

• Use the following spectrum analyzer settings:
• Set the RBW ≥ DTS bandwidth, centered on the test channel.
• Set VBW ≥ 3 x RBW.
• Set Span ≥ 3 x RBW.
• Sweep: Auto.
• Detector function: Peak.
• Trace: Max hold.
• Allow trace to stabilize.
• Use the marker-to-peak function to set the marker to the peak of the emission.
• The indicated level is the peak output power, after any corrections for external attenuators and cables.
• A plot of the test results and setup description shall be included in the test report.

Using a Broadband Power Meter for Testing: Remove the antenna from the EUT and then connect a low loss RF cable from the antenna port to the broadband power meter.

5.4. TEST RESULT

Pass. Please refer to the Appendix for Bluetooth LE RF Conducted Test Data.

Note: The test results including the cable lose.

6. 6DB BANDWIDTH AND OCCUPIED BANDWIDTH

6.1. LIMIT

According to 15.247(a)(2) and IC RSS-247 5.2(a), Systems using digital modulation techniques may operate in the 902–928 MHz, 2400–2483.5 MHz, and 5725–5850 MHz bands. The minimum 6 dB bandwidth shall be at least 500 kHz.

6.2. TEST SETUP

Diagram shows a Spectrum Analyzer connected via RF cable to an EUT (Equipment Under Test).

6.3. TEST PROCEDURE

Remove the antenna from the EUT and then connect a low loss RF cable from the antenna port to the spectrum analyzer.

For 6dB Bandwidth Measurement:

• Span = approximately 1.5 to 5 times the OBW, centered on the test channel.
• RBW = 100KHz.
• VBW ≥ 3 x RBW
• Sweep = auto;
• Detector function = peak
• Trace = max hold
• All the trace to stabilize, use the marker-to-peak function to set the marker to the peak of the emission, use the marker-delta function to measure and record the 6dB down bandwidth of the emission.

For 99% Occupied Bandwidth Measurement:

• Span = approximately 1.5 to 5 times the OBW, centered on the test channel.
• RBW = 1% to 5% of the OBW.
• VBW ≥ 3 x RBW
• Sweep = auto;
• Detector function = peak
• Trace = max hold
• Use the 99% power bandwidth function of the instrument to measure the Occupied Bandwidth and recoded.

6.4. TEST RESULT

Please refer to the Appendix for Bluetooth BLE RF Conducted Test Data.

7. POWER SPECTRAL DENSITY

7.1. LIMIT

According to 15.247(e) and IC RSS-247 5.2(b), For digitally modulated systems, the power spectral density conducted from the intentional radiator to the antenna shall not be greater than 8dBm in any 3kHz band during any time interval of continuous transmission.

7.2. TEST SETUP

Diagram shows a Spectrum Analyzer connected via RF cable to an EUT (Equipment Under Test).

7.3. TEST PROCEDURE

Remove the antenna from the EUT and then connect a low loss RF cable from the antenna port to the spectrum analyzer.

• Use the following spectrum analyzer settings:
• Set analyzer center frequency to DTS channel center frequency.
• Set the span to 1.5 times the DTS bandwidth.
• Set the RBW to: 3KHz ≤ RBW ≤ 100KHz.
• Set the VBW ≥ 3 x RBW.
• Detector = peak.
• Sweep time = auto couple.
• Trace mode = max hold.
• Allow trace to fully stabilize.
• Use the peak marker function to determine the maximum amplitude level within the RBW.
• If measured value exceeds limit, reduce RBW (no less than 3 kHz) and repeat.

7.4. TEST RESULT

Pass. Please refer to the Appendix for Bluetooth LE RF Conducted Test Data.

8. RADIATED EMISSIONS AND RADIATED BAND EDGES MEASUREMENT

8.1. LIMIT

According to §15.247(d) and IC RSS-247, radiated emissions which fall in the restricted bands, as defined in § 15.205(a), must also comply with the radiated emission limits specified in § 15.209(a) (see § 15.205(c)).

Limits of Spurious Emissions

Remark:

• a) The lower limit shall apply at the transition frequencies.
• b) Emission level (dBuV/m) = 20*log Emission level (uV/m).
• c) For frequencies above 1000MHz, the field strength limits are based on average detector, however, the peak field strength of any emission shall not exceed the maximum permitted average limits, specified above by more than 20dB under any condition of modulation.
• d) Spurious Radiated Emissions measurements starting below or at the lowest crystal frequency.

8.2. TEST SETUP

Block Diagram of Radiated Emission Below 30MHz: Diagram shows a Semi-anechoic 3m Chamber with an EUT on a turntable, connected to a PC System, Spectrum Analyzer, AMP, and Combining Network. An EMI Receiver is positioned at 3m distance. A loop antenna is shown.

Block Diagram of Radiated Emission From 30MHz to 1GHz: Diagram shows a Semi-anechoic 3m Chamber with an EUT on a turntable (0.8m height), connected to a PC System, Spectrum Analyzer, AMP, and Combining Network. An antenna (e.g., Bilog) is positioned at 3m distance.

Block Diagram of Radiated Emission Above 1GHz: Diagram shows an Anechoic 3m Chamber with an EUT on a turntable (1.5m height), connected to a PC System, Spectrum Analyzer, AMP, and Combining Network. An antenna (e.g., Horn) is positioned at 3m distance. Absorbers are shown.

8.3. TEST PROCEDURE

• a) Below 1GHz measurement the EUT is placed on a turntable which is 0.8m above ground plane, and above 1GHz measurement EUT was placed on a low permittivity and low loss tangent turn table which is 1.5m above ground plane.
• b) Maximum procedure was performed by raising the receiving antenna from 1m to 4m and rotating the turn table from 0 degree to 360 degree to acquire the highest emissions from EUT.
• c) And also, each emission was to be maximized by changing the polarization of receiving antenna both horizontal and vertical.
• d) Repeat above procedures until all frequency measurements have been completed.
• e) Radiated emission test frequency band from 9KHz to 25GHz.
• f) The radiation measurements are performed in X, Y, Z axis positioning for Transmitting mode, and record the worst case in this report.

Distance between test antenna and EUT:

Setting test receiver/spectrum:

8.4. TEST RESULT

Pass.

Remark:

• a) Pre-scan all modes and recorded the worst case in this report.
• b) Radiated emission test from 9KHz to 10th harmonic of fundamental was verified, and the emission levels from 9kHz to 30MHz are attenuated 20dB below the limit and not recorded in report.

Radiated Emission Test Data (30MHz to 1GHz)

Environmental Conditions: 24.6°C, 53.4% RH

Worst Test Mode: TM1(BLE 1M)

Test Engineer: Jacey Fu

Polarity: Horizontal

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit. - Emission Level

Polarity: Vertical

Radiated Emission Test Data (Above 1GHz)

Environmental Conditions: 24.6°C, 53.4% RH

Test Engineer: Jacey Fu

Lowest Channel (Worst Case: BLE 1M_2402MHz)

Middle Channel (Worst Case: BLE 1M_2440MHz)

Highest Channel (Worst Case: BLE 1M_2480MHz)

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit. - Emission Level

Testing is carried out with frequency rang 9kHz to the tenth harmonics. The measurements greater than 20dB below the limit from 18GHz to 25GHz.

Radiated Band Edges Test Data

Environmental Conditions: 24.6°C, 53.4% RH

Test Engineer: Jacey Fu

Lowest Channel (Worst Case: BLE 1M_2402MHz)

Highest Channel (Worst Case: BLE 1M_2480MHz)

Remark: Emission Level = Reading + Factor; Factor = Antenna Factor + Cable Loss – Pre-amplifier; Margin= Limit. - Emission Level

9. POWER LINE CONDUCTED EMISSIONS

9.1. LIMIT

According to the rule FCC Part 15.207 and IC RSS-Gen 8.8, Conducted emissions limit, the limit for a wireless device as below:

Remark:

• a) The lower limit shall apply at the transition frequencies.
• b) The limit decreases linearly with the logarithm of the frequency in the range 0.15 to 0.50MHz.

9.2. TEST SETUP

Diagram: Diagram shows an EUT & Auxiliary Equipment connected to an EMI Receiver via a LISN (Line Impedance Stabilization Network). A reference ground plane and a vertical reference plane are depicted.

9.3. TEST PROCEDURE

Test frequency range: 150KHz-30MHz

• a) The mains terminal disturbance voltage test was conducted in a shielded room.
• b) The EUT was connected to AC power source through a LISN 1 (Line Impedance Stabilization Network) which provides a 50Ω/50μH + 5Ω linear impedance. The power cables of all other units of the EUT were connected to a second LISN 2, which was bonded to the ground reference plane in the same way as the LISN 1 for the unit being measured. A multiple socket outlet strip was used to connect multiple power cables to a single LISN provided the rating of the LISN was not exceeded.
• c) The tabletop EUT was placed upon a non-metallic table 0.8m above the ground reference plane. And for floor-standing arrangement, the EUT was placed on the horizontal ground reference plane,
• d) The test was performed with a vertical ground reference plane. The rear of the EUT shall be 0.4 m from the vertical ground reference plane. The vertical ground reference plane was bonded to the horizontal ground reference plane. The LISN 1 was placed 0.8 m from the boundary of the unit under test and bonded to a ground reference plane for LISNs mounted on top of the ground reference plane. This distance was between the closest points of the LISN 1 and the EUT. All other units of the EUT and associated equipment was at least 0.8 m from the LISN 2.
• e) In order to find the maximum emission, the relative positions of equipment and all of the interface cables must be changed according to ANSI C63.10 on conducted measurement.

9.4. TEST RESULT

Pass.

Remark:

• a) AC Power line conducted emissions pre-test both at AC 120V/60Hz and AC 240V/50Hz modes, recorded worst case.
• b) Worst-case mode and channel used for 150KHz~30MHz power line conducted emissions was determined to be BLE 1M_2402MHz.

Test Plots and Data of Conducted Emissions (Worst Case: BLE 1M_2402MHz)

Environmental Conditions: 24.6°C, 53.4% RH

Test Voltage: AC 120V/60Hz

Test Engineer: Jacey Fu

Test Power Line: Live

Remark: Emission Level = Reading + Correct Factor; Correct Factor = LISN Factor + Cable Loss + Pulse Limiter Attenuation Factor Margin= Emission Level - Limit.

Test Power Line: Neutral

Remark: Emission Level = Reading + Correct Factor; Correct Factor = LISN Factor + Cable Loss + Pulse Limiter Attenuation Factor Margin= Emission Level - Limit.

10. PHOTOGRAPHS OF TEST SETUP

Please refer to separated files for Test Setup Photos of the EUT.

11. EXTERNAL PHOTOGRAPHS OF THE EUT

Please refer to separated files for External Photos of the EUT.

12. INTERNAL PHOTOGRAPHS OF THE EUT

Please refer to separated files for Internal Photos of the EUT.