Shenzhen CTA Testing Technology Co., Ltd. TEST REPORT

1. TEST STANDARDS

The tests were performed according to following standards:

• FCC Rules Part 15.249: Operation within the bands 902 - 928 MHz, 2400 - 2483.5 MHz, 5725 - 5875 MHz, and 24.0 - 24.25 GHz.
• ANSI C63.10:2013 : American National Standard for Testing Unlicensed Wireless Devices
• ANSI C63.4: 2014: American National Standard for Methods of Measurement of Radio-Noise Emissions from Low-Voltage Electrical and Electronic Equipment in the Range of 9 kHz to 40GHz

2. SUMMARY

2.1. General Remarks

Date of receipt of test sample: Jun.15, 2024

Testing commenced on: Jun.15, 2024

Testing concluded on: Jun. 22, 2024

2.2. Product Description

Name of EUT: FLOW Lite 84-Key Triple Mode Low-Profile Mechanical Keyboard

List Model: OE921

Power Rating: DC 3.7V From battery and DC 5.0V From external circuit

PC information (Auxiliary test supplied by testing Lab): Model: E470C, Trade Mark: thinkpad

Hardware version: V2.0

Software version: 6BEAA702

Sample ID: CTA240617015-1# (Engineer sample), CTA240617015-2# (Normal sample)

Operation frequency: 2405-2475MHz

Modulation: GFSK

Antenna Type: PCB antenna

Antenna Gain: -1.66 dBi

2.3. Equipment Under Test

Power supply system utilised: DC 3.7V From Battery and DC 5.0V From external circuit

Power supply voltage options: 230V / 50 Hz, 120V / 60Hz, 12 V DC, 24 V DC, Other.

2.4. Short description of the Equipment under Test (EUT)

This is a FLOW Lite 84-Key Triple Mode Low-Profile Mechanical Keyboard. For more details, refer to the user's manual of the EUT.

2.5. EUT operation mode

The Applicant uses a key to control the EUT for staying in continuous transmitting and receiving mode for testing. There are 16 channels provided to the EUT. Channel Low, Mid, and High were selected for testing.

Test Frequencies:

Selected Test Frequencies:

2.6. Block Diagram of Test Setup

The test setup consists of the EUT connected to a PC, receiving DC 5V power from the PC.

2.7. Modifications

No modifications were implemented to meet testing criteria.

3. TEST ENVIRONMENT

3.1. Address of the test laboratory

Shenzhen CTA Testing Technology Co., Ltd. Room 106, Building 1, Yibaolai Industrial Park, Qiaotou Community, Fuhai Street, Bao'an District, Shenzhen, China

3.2. Test Facility

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

• FCC-Registration No.: 517856, Designation Number: CN1318
• Shenzhen CTA Testing Technology Co., Ltd. is listed on the US Federal Communications Commission list of test facilities recognized to perform electromagnetic emissions measurements.
• Industry Canada Registration Number: 27890, CAB identifier: CN0127. The Laboratory is registered by Certification and Engineering Bureau of Industry Canada for radio equipment testing.
• A2LA-Lab Cert. No.: 6534.01. Shenzhen CTA Testing Technology Co., Ltd. is listed by American Association for Laboratory Accreditation to perform electromagnetic emission measurement.

The 3m-Semi anechoic test site fulfils CISPR 16-1-4 according to ANSI C63.10 and CISPR 16-1-4:2010.

3.3. Environmental conditions

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

Radiated Emission:

• Temperature: 23 °C
• Humidity: 48 %
• Atmospheric pressure: 950-1050mbar

AC Main Conducted testing:

• Temperature: 24 °C
• Humidity: 45 %
• Atmospheric pressure: 950-1050mbar

Conducted testing:

• Temperature: 24 °C
• Humidity: 45 %
• Atmospheric pressure: 950-1050mbar

3.4. Summary of measurement results

3.5. Statement of the measurement uncertainty

• Conducted Emission Expanded Uncertainty = 2.23dB, k=2
• Radiated emission expanded uncertainty(9kHz-30MHz) = 3.08dB, k=2
• Radiated emission expanded uncertainty(30MHz-1000MHz) = 4.42dB, k=2
• Radiated emission expanded uncertainty(Above 1GHz) = 4.06dB, k=2

3.6. Equipments Used during the Test

4. TEST CONDITIONS AND RESULTS

4.1. AC Power Conducted Emission

TEST CONFIGURATION

The test setup involves the EUT placed in a shielded room, connected to a LISN and a test receiver.

TEST PROCEDURE

The equipment was set up to simulate typical usage. The EUT was placed on a wooden table 0.8 meters above the ground plane. Support equipment and I/O cables were positioned according to ANSI C63.10. Emissions were measured on each current carrying line using a spectrum analyzer/receiver connected to the LISN. Scans were performed with Line 1 and Line 2 connected to the analyzer/receiver, and the analyzer/receiver scanned from 150 KHz to 30MHz.

AC Power Conducted Emission Limit

* Decreases with the logarithm of the frequency.

TEST RESULTS

Remarks:

• All modes of GFSK (Low, Middle, High channels) were tested, and the worst case for GFSK CH19 is reported.
• Both 120 VAC, 50/60 Hz and 240 VAC, 50/60 Hz power supplies were tested; the worst result for 120 VAC, 60 Hz is reported.

Conducted Emission Data (120V/60Hz, L)

Conducted Emission Data (120V/60Hz, N)

Note for tables: 1).QP Value (dBμV)= QP Reading (dBμV)+ Factor (dB); 2). Factor (dB)=insertion loss of LISN (dB) + Cable loss (dB); 3). QPMargin (dB) = QP Limit (dBμV) - QP Value (dBμV); 4). AVMargin(dB) = AV Limit (dBμV) - AV Value (dBμV)

4.2. Radiated Emission and Band Edges

TEST CONFIGURATION

Frequency range 9 KHz – 30MHz

The test setup includes the EUT on a turntable, a loop antenna, a test receiver, and a ground plane. The EUT is at 0.8m height, and the antenna is at 3m distance.

Frequency range 30MHz – 1000MHz

The test setup includes the EUT on a turntable, a test receiver, and a ground plane, connected via a coaxial cable. The EUT is at 0.8m height.

Frequency range above 1GHz-25GHz

The test setup is within a semi-anechoic chamber. The EUT is on a turntable (0.8m height), with an antenna at 3m distance (1m to 4m height adjustable). A measurement instrument and controller are located in a control room.

TEST PROCEDURE

The EUT was placed on a turntable 0.8m above the ground plane. The receiving antenna was raised from 1m to 4m, and the turntable rotated from 0° to 360° to acquire the highest emissions. Polarization was changed between horizontal and vertical. Procedures were repeated until all measurements were completed. The EUT operates from 26MHz to 1910MHz, so radiated emission tests cover 9KHz to 25GHz.

Test Antenna Distances:

Test Receiver/Spectrum Setting:

Field Strength Calculation

The field strength is calculated by adding the Antenna Factor and Cable Factor and subtracting the Amplifier Gain from the measured reading. Formula: FS = RA + AF + CL - AG, where FS = Field Strength, RA = Reading Amplitude, AF = Antenna Factor, CL = Cable Attenuation Factor, AG = Amplifier Gain.

RADIATION LIMIT

According to FCC Part 15.249, the field strength of emissions from intentional radiators operated within 2400MHz-2483.5 MHz shall not exceed 94dBμV/m (50mV/m).

FCC Part 15.249(d) states that emissions radiated outside of specified frequency bands, except for harmonics, shall be attenuated by at least 50 dB below the level of the fundamental or to the general radiated emission limits in §15.209, whichever is lesser. Radiated emissions falling in restricted bands must comply with §15.209(a).

Radiated emission limits:

TEST RESULTS

Radiated Emission (30MHz-1GHz) - Horizontal

Note: 1).Level (dBμV/m)= Reading (dBμV)+ Factor (dB/m); 2). Factor(dB/m)=Antenna Factor (dB/m) + Cable loss (dB) - Pre Amplifier gain (dB); 3). Margin(dB) = Limit (dBμV/m) - Level (dBμV/m)

Radiated Emission (30MHz-1GHz) - Vertical

Note: 1).Level (dBμV/m)= Reading (dBμV)+ Factor (dB/m); 2). Factor(dB/m)=Antenna Factor (dB/m) + Cable loss (dB) - Pre Amplifier gain (dB); 3). Margin(dB) = Limit (dBμV/m) - Level (dBμV/m)

Radiated Emission (1GHz-25GHz) - 2405 MHz

Radiated Emission (1GHz-25GHz) - 2405 MHz (Vertical)

Radiated Emission (1GHz-25GHz) - 2441 MHz

Radiated Emission (1GHz-25GHz) - 2441 MHz (Vertical)

Radiated Emission (1GHz-25GHz) - 2475 MHz

Radiated Emission (1GHz-25GHz) - 2475 MHz (Vertical)

REMARKS: 1. Emission level (dBuV/m) =Raw Value (dBuV)+Correction Factor (dB/m); 2. Correction Factor (dB/m) = Antenna Factor (dB/m)+Cable Factor (dB)- Pre-amplifier; 3. Margin value = Limit value- Emission level; 4. PK detector measured value is below average limit; 5. The other emission levels were very low against the limit.

Results of Band Edges Test (Radiated) - 2405 MHz

Results of Band Edges Test (Radiated) - 2405 MHz (Vertical)

Results of Band Edges Test (Radiated) - 2475 MHz

Results of Band Edges Test (Radiated) - 2475 MHz (Vertical)

Note: 1) Emission level (dBuV/m) = Meter Reading+ antenna Factor+ cable loss- preamp factor. 2) Margin value = Limits-Emission level. 3) PK detector measured value is below average limit. 4) The other emission levels were very low against the limit. 5) RBW 1MHz VBW 3MHz Peak detector is for PK value; RBW 1MHz VBW 10Hz Peak detector is for AV value.

4.3. 20dB Bandwidth Measurement

TEST CONFIGURATION

The EUT was connected to a spectrum analyzer through an attenuator.

TEST PROCEDURE

The bandwidth of the fundamental frequency was measured by spectrum analyzer with 30KHz RBW and 300KHz VBW. The 20dB bandwidth is defined as the total spectrum power higher than peak power minus 20dB.

LIMIT

N/A

TEST RESULTS

Note: The test results include the cable loss.

The spectrum analyzer screenshots show the occupied bandwidth and 20dB bandwidth measurements for GFSK modulation at Low, Mid, and High channels.

4.4. Antenna Requirement

Standard Applicable

For intentional devices, according to FCC 47 CFR Section 15.203, the radiator must be designed to use only the antenna furnished by the responsible party. According to FCC 47 CFR Section 15.247 (c), if transmitting antennas with directional gain greater than 6dBi are used, the power shall be reduced by the amount the gain exceeds 6dBi.

Antenna Information

The maximum gain of the antenna was -1.66 dBi.

Remark: The antenna gain is provided by the customer. Shenzhen CTA Testing Technology Co., Ltd. does not assume responsibility for the accuracy of customer-provided data.

5. Test Setup Photos of the EUT

Photo 1: EUT (laptop) placed on a wooden table with associated equipment on a side table.

Photo 2: EUT positioned on a turntable inside a semi-anechoic chamber, with test equipment and antennas visible.

Photo 3: Close-up view of the EUT setup in the semi-anechoic chamber, showing the turntable and sound-absorbing material.

6. Test Photos of the EUT

Reference to the test report No. CTA24061701501. This section marks the end of the report.