THE MINISTRY OF INFORMATION AND COMMUNICATIONS ___________ No. 10/2021/TT-BTTTT | THE SOCIALIST REPUBLIC OF VIETNAM Independence - Freedom - Happiness __________ Hanoi, October 28, 2021 |
CIRCULAR
Promulgating “National technical regulation on short range device (SRD) - Radio equipment to be used in the 40 GHz to 246 GHz frequency range”
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Pursuant to the Law on Standards and Technical Regulations dated June 29, 2006;
Pursuant to the Law on Telecommunications dated November 23, 2009;
Pursuant to the Law on Radio Frequencies dated November 23, 2009;
Pursuant to Decree No. 127/2007/ND-CP dated August 1, 2007 of the Government detailing and guiding the implementation of a number of articles of the Law on Standards and Technical Regulations;
Pursuant to Decree No. 78/2018/ND-CP dated May 16, 2018 of the Government amending and supplementing a number of articles of the Decree No. 127/2007/ND-CP dated August 1, 2007 of the Government detailing the implementation of a number of articles of the Law on Standards and Technical Regulations;
Pursuant to Decree No. 17/2017/ND-CP dated February 17, 2017 of the Government defining the functions, tasks, powers and organizational structure of the Ministry of Information and Communications;
At the proposal of the Director General of the Department of Science and Technology,
The Minister of Information and Communications hereby promulgates the Circular stipulating the national technical regulation on short range device (SRD) - Radio equipment to be used in the 40 GHz to 246 GHz frequency range.
Article 1. This Circular is promulgated together with the National Technical Regulation on short range device (SRD) -Radio equipment to be used in the 40 GHz to 246 GHz frequency range (QCVN 123: 2021/BTTTT).
Article 2. This Circular takes effect from July 01, 2022.
Article 3. The Chief of Office, Director General of the Department of Science and Technology, Heads of agencies and units under the Ministry of Information and Communications, Directors of Departments of Information and Communications of provinces and centrally-run cities and relevant organizations and individuals shall implement this Circular./.
The Minister
NGUYEN MANH HUNG
THE SOCIALIST REPUBLIC OF VIETNAM
QCVN 123:2021/BTTTT
NATIONAL TECHNICAL REGULATION ON SHORT RANGE DEVICE (SRD) - RADIO EQUIPMENT TO BE USED IN THE 40 GHZ TO 246 GHZ FREQUENCY RANGE
Hanoi – 2021
Preface
QCVN 123:2021/BTTTT compiled by the Authority of Telecommunications, submitted by the Department of Science and Technology, appraised by the Ministry of Science and Technology, and issued by the Ministry of Information and Communications together with Circular No. 10/2021/TT -BTTTT dated October 28, 2021
NATIONAL TECHNICAL REGULATION ON SHORT RANGE DEVICE (SRD) - RADIO EQUIPMENT TO BE USED IN THE 40 GHZ TO 246 GHZ FREQUENCY RANGE
1. GENERAL PROVISIONS
1.1. Scope of regulation
This Regulation applies to general types of transmitting device, short range device (SRD) – radio transmitting and receiving equipment, including the equipment used for alarms, telemetry, telecommand, data transmission, operating in the 40 GHz to 246 GHz frequency range specified in Table 1 of this Regulation in the following cases:
- With a radio frequency output connection and dedicated antenna or with an integral antenna;
- With all types of modulation;
- Fixed stations, mobile stations and portable stations.
Table 1 – Frequency bands used for short range devices within the 40 GHz to 246 GHz frequency range
Frequency Band | Applications |
61.0 GHz to 61.5 GHz | Use for general purposes |
122 GHz to 123 GHz |
244 GHz to 246 GHz |
This Regulation applies to products and goods that are short-range devices - radio equipment with HS codes specified in Appendix D.
1.2. Subjects of application
This Regulation applies to Vietnamese and foreign agencies, organizations and individuals engaged in the production and business of equipment covered by this Regulation in the Vietnamese territory.
1.3. Normative references
ETSI TR 100 028 (V1.4.1) (all parts): “Electromagnetic compatibility and Radio spectrum Matters (ERM); Uncertainties in the measurement of mobile radio equipment characteristics”.
CEPT/ERC Recommendation 74-01: “Unwanted emissions in the spurious domain”, Hradec Kralove, Cardiff 2011.
Recommendation ITU-R SM.329-12 (09/2012): “Unwanted emissions in the spurious domain, SM Series, Spectrum management”.
CISPR 16 (2006) (parts 1-1, 1-4 and 1-5): “Specification for radio disturbance and immunity measuring apparatus and methods”.
ETSI TR 102 273 (V 1.2.1) (all parts): “Electromagnetic compatibility and Radio spectrum Matters (ERM); Improvement on Radiated Methods of Measurement (using test site) and evaluation of the corresponding measurement uncertainties”.
Recommendation ITU-T O.153: “Basic parameters for the measurement of error performance at bit rates below the primary rate”.
ETSI TS 103 052: “Electromagnetic compatibility and Radio spectrum Matters (ERM); Radiated measurement methods and general arrangements for test sites up to 100 GHz”.
1.4 Interpretation of terms
1.4.1 Alarm
Use of radio communication for indicating an alarm condition at a distant location
1.4.2 Artificial antenna
Non-radiating dummy load equal to the nominal impedance specified by the manufacturer
1.4.3 Assigned frequency band
Frequency band within which the device is authorized to operate and to perform the intended functions of the device.
1.4.4 Dedicated antenna
Removable antenna supplied and tested with the radio equipment, designed as an indispensable part of the equipment
1.4.5 Direct sequence spread spectrum
Form of modulation where a combination of data to be transmitted and a fixed code sequence is used to directly modulate a carrier, e.g. by phase shift keying.
NOTE: The code rate determines the occupied bandwidth.
1.4.6 Environmental profile
Range of environmental conditions under which equipment within the scope of this regulation is required to comply with the provisions of this regulation.
1.4.7 Fixed station
Equipment intended for use in a fixed location
1.4.8 Frequency hopping spread spectrum
Spread spectrum technique in which the transmitter signal occupies a number of frequencies in time, each for some period of time, referred to as the dwell time
NOTE: Transmitters and receivers follow the same frequency hop pattern. The number of hop positions and the bandwidth per hop position determine the occupied bandwidth.
1.4.9 Integral antenna
Permanent fixed antenna, which may be built-in, designed as an indispensable part of the equipment
1.4.10 Mobile station
Equipment normally fixed in a vehicle or used as a transportable station.
1.4.11 Necessary bandwidth
Width of the emitted frequency band which is sufficient to ensure the transmission of information at the rate and with the quality required under specified conditions
NOTE: The necessary bandwidth including the frequency tolerances is accommodated within the assigned frequency band.
1.4.12 Occupied bandwidth
Width of a frequency band such that, below the lower and above the upper frequency limits, the mean powers emitted are each equal to 0,5 % of the total mean power of a given emission
NOTE: This corresponds to the -23 dBc bandwidth of the signal.
1.4.13 Operating frequency
Nominal frequency at which equipment is operated; this is also referred to as the operating center frequency
NOTE: Equipment may be able to operate at more than one operating frequency.
1.4.14 Operating frequency range
Range of operating frequencies over which the equipment can be adjusted through tuning, switching or reprogramming
1.4.15 Portable station
Equipment that may be carried
1.4.16 Power spectral density
Ratio of the amount of power to the used radio measurement bandwidth
NOTE: It is expressed in units of dBm/Hz or as a power in dBm with respect to the used bandwidth. In case of measurement with a spectrum analyser the measurement bandwidth is equal to the RBW.
1.4.17 Radiated measurements
Measurements which involve the absolute measurement of a radiated field
1.4.18 Spread spectrum
Modulation technique in which the energy of a transmitted signal is spread throughout a large portion of the frequency spectrum
1.4.19 Ultra low power equipment
Equipment using transmit envelope power below the receiver and idle/standby transmitter limits given in CEPT/ERC Recommendation 74-01.
1.4.20 Unwanted emissions
Emission on a frequency or frequencies which are outside the necessary bandwidth and the level of which may be reduced without affecting the corresponding transmission of information
NOTE: Unwanted emissions include harmonic emissions, parasitic emissions, intermodulation products and frequency conversion products.
1.5 Symbols
dB deciBel
dBc Relative deciBel (compared to the maximum power density of the transmitted signal)
dBm decibel corresponding to 1mW
f Frequency
P Power
t Time
λ Wavelength
1.6 Abbreviations
BW | Bandwidth |
CEPT | European Conference of Postal and Telecommunications Administrations |
CISPR | Comité international special des perturbations radioélectriques |
e.i.r.p. | equivalent isotropical radiated power |
e.r.p. | effective radiated power |
ERC | European Radiocommunication Committee |
EUT | Equipment Under Test |
FHSS | Frequency Hopping Spread Spectrum |
FSL | Free Space Loss |
NSA | Normalized Site Attenuation |
OATS | Open Area Test Site |
OBW | Occupied Bandwidth |
OOB | Out-of-Band |
PD | Power Density |
PDL | Power Density Limit |
PSD | Power Spectral Density |
R&TTE | Radio and Telecommunications Terminal Equipment |
RBW | Resolution Bandwidth |
RF | Radio Frequency |
RMS | Root Mean Square |
SRD | Short Range Device |
TX | Transmitter |
VBW | Video Bandwidth |
2. TECHNICAL SPECIFICATIONS
The technical specifications of this regulation apply in the operating environment of the equipment which shall be declared by the manufacturer. The equipment shall comply with all technical requirements of this regulation when operating within the boundary limits of the declared operating environment.
2.1. Requirements for transmitters
2.1.1. RF output power
2.1.1.1. Definition
The RF output power is the mean equivalent isotropic radiated power during the transmission of a data package. In the case of equipment performing power control, the mean e.i.r.p. is the highest power level of the transmitter power control range during the transmission cycle.
2.1.1.2. Limits
The maximum RF output power corresponds to the system operating at the highest declared power level. For smart antenna systems and directional antennas, this limit corresponds to the configuration which results in the highest e.i.r.p.
The RF output power limit in the broadband operation mode shall not exceed the value specified in Table 2 below.
Table 2 - RF output power limits
Frequency Band | RF output power (e.i.r.p.) | Applications | Remarks |
61.0 GHz to 61.5 GHz | 100 mW (20 dBm) | Use for general purposes | |
122 GHz to 123 GHz | 100 mW (20 dBm) | Use for general purposes | |
244 GHz to 246 GHz | 100 mW (20 dBm) | Use for general purposes | |
2.1.1.3. Measurement methods
The measurement methods are specified in 3.2.1.
2.1.2 Permitted operating frequency range
2.1.2.1. Definition
The permitted operating frequency range is the frequency range over which the equipment is authorized to operate. The manufacturer shall declare the permitted operating frequency range.
fL means the lowest operating frequency and fH means the highest operating frequency. If equipment is able to operate in different modes and on different frequency bands, these frequencies shall be reported for each mode and frequency band.
2.1.2.2. Limits
The frequency range of the equipment measured from the lowest frequency (fL) to the highest frequency (fH) is limited by the power spectrum envelope. In equipment that allows adjustment or selection of different operating frequencies, the power envelope occupies different positions in the allocated frequency band. This frequency range is defined by the lowest values fL and the highest values fH, determined from the adjustment of the device from the lowest operating frequency to the highest operating frequency.
The occupied bandwidth (equal to 99% of the wanted radiated power) and the required bandwidth shall be within the assigned frequency band.
The operating frequency range of the equipment shall be within the frequency band segments specified in Table 1 of this Regulation.
2.1.2.3. Measurement methods
The measurement methods are specified in 3.2.2.
2.1.3. Out-of-band emissions
According to CEPT/ERC recommendation 74-01 and Recommendation ITU-R SM.329-12, the boundary between the out-of-band emission domain and spurious emission domain is ±250 % of the required bandwidth from the central emission frequency.
2.1.3.1. Definition
Out-of-band emissions are emissions on one or more frequencies outside the required bandwidth, resulting from a modulation process, but excluding spurious emissions.
Out-of-band emissions are determined in accordance with a measurement of the mean spectral density (e.i.r.p.) under normal operating conditions.
The measurement results of fH and fL are used to determine the occupied bandwidth of the device.
The occupied bandwidth (fH - fL) is used to determine the out-of-band emission domain and spurious emission domain.
2.1.3.2. Limits
The boundary values of the out-of-band emission domain and spurious emission domain depend on the occupied bandwidth of the EUT.
The boundary limit is determined as follows:
F1 = center frequency of OBW [GHz] - (2.5 * (fH - fL))
F2 = center frequency of OBW [GHz] + (2.5 * (fH - fL))
Where, the center frequency of the OBW is the center frequency of the signal.
This calculation is given to determine the out-of-band and spurious emission domain boundaries, which will be greater than/less than the maximum value in the permitted operating range (see Figure 1).
Figure 1 - Overview of OOB/spurious emission dependence on OBW
In addition, it is possible to calculate F1/F2 as follows: If F1/F2 is considered as the theoretical lower or upper frequency which come out of the calculation based on 250 % of the maximum value of the OBW (see Table 2). Therefore, the amplitude between OOB and spurious emission will be fixed at the frequency given in Table 3 below (normally F1/F2 is calculated as 250 % of the center frequency of the signal).
Table 3 - Limits of frequency values F1 and F2, based on the maximum theoretical OBW of the EUT
Frequency Band | Center frequency | Maximum OBW | F1 | F2 |
61.0 GHz to 61.5 GHz | 61.25 GHz | 500 MHz | 60 GHz | 62.5 GHz |
122 GHz to 123 GHz | 122.5 GHz | 1 GHz | 120 GHz | 125 GHz |
244 GHz to 246 GHz | 245 GHz | 2 GHz | 240 GHz | 250 GHz |
The value of the radiated power density based on the RMS value in the OOB range (between F1 ≤ f < fL and fH < f ≤ F2) shall not exceed the values specified in Tables 4 and 5 below.
Table 4 - Out-of-band emission domain
Frequency [GHz] | RMS power density [dBm/MHz] |
F1 ≤ f < fL | See Table 6 |
fH < f ≤ F2 | See Table 6 |
Table 5: Limits for out-of-band radiation
Frequency band | OOB limit [dBm/MHz] |
61.0 GHz to 61.5 GHz | -10 dBm/MHz |
122 GHz to 123 GHz | -10 dBm/MHz |
244 GHz to 246 GHz | -15 dBm/MHz |
2.1.3.3. Measurement methods
The measuring methods are specified in 3.2.3
2.1.4. Spurious emission
2.1.4.1. Definition
Spurious emissions are emissions on one or more frequencies that are outside the required bandwidth and whose value can be reduced without affecting the transmission of information. Spurious emissions include harmonic emissions, parasitic emissions, intermodulation components and frequency conversion components, but exclude out-of-band emissions.
Spurious emissions are measured as power spectral density under normal operating conditions. According to CEPT/ERC recommendation 74-01 and Recommendation ITU-R SM.329-12, the boundary between spurious and out-of-band emission domains emission is ±250 % of the required bandwidth of the center frequency emission.
The frequency ranges to be evaluated in the spurious emission domain are:
- Frequency f < F1 [GHz]
and
- Frequency f > F2 [GHz]
The way to determine the values of these frequencies is given in 2.1.3.2, the minimum and maximum values are given in Table 3 above.
2.1.4.2. Limits
The power of spurious emissions shall not exceed the values specified in Table 6 below.
Table 6 - Spurious emission limits
Frequency range (MHz) | Limit values for spurious emission | Type of detector |
47 to 74 | -54 dBm e.r.p. | Quasi-peak |
87.5 to 118 | -54 dBm e.r.p. | Quasi-peak |
174 to 230 | -54 dBm e.r.p. | Quasi-peak |
470 to 862 | -54 dBm e.r.p. | Quasi-peak |
Otherwise in frequency bands 30 to 1 000 | -36 dBm e.r.p. | Quasi-peak |
1 000 to 300 000 | -30 dBm e.i.r.p. | Mean value (See NOTE) |
NOTE: Parameters to be set up for testing - RBW: 1MHz; - VBW: 3MHz; - Detector: rms; - Sweep time: At least a radar cycle, 100 ms at the maximum. |
According to CEPT/ERC 74-01 recommendations, spurious emissions are measured to the second harmonic of the fundamental frequency (in this case, the maximum frequency is 90 GHz).
The measured bandwidth is specified as follows:
• 100 kHz between 30 MHz and 1 GHz frequencies;
• 1 MHz for frequencies above 1 GHz.
2.1.4.3. Measurement methods
The measurement methods are specified in 3.2.4.
2.2. Requirements for receivers
2.2.1. Unwanted emissions
2.2.1.1. Definition
Unwanted emissions from the receiver are radiations of any frequency by equipment and antennas. The unwanted emission shall be measured by its effective radiated power including: Enclosure radiation and integrated equipment or with a dedicated antenna.
2.2.1.2. Limits
Unwanted emitted power:
- shall not exceed 2 nW (-57 dBm) in the 30 MHz to 1 GHz frequency range;
- shall not exceed 20 nW (-47 dBm in the 1 MHz reference bandwidth) in the frequency range above 1 GHz.
The upper limit frequency is the EUT's second harmonic or 300 GHz, whichever is lower.
The measured unwanted emissions shall be included in the test report.
2.2.1.3. Measurement methods
The measurement methods are specified in 3.3.
3. MEASUREMENT METHODS
3.1. Requirements for test
3.1.1. Environmental conditions for testing
The tests specified in this regulation shall be carried out within the boundary limits of the test environment.
3.1.1.1. General conditions for testing
3.1.1.1.1. Temperature and humidity
The normal temperature and humidity conditions for the tests shall be within the following ranges:
- Temperature: from +15°C to +35°C;
- Humidity: from 20% to 75%.
3.1.1.1.2. Normal power supply for testing
a) Main voltage
The supply voltage connected to the test equipment shall be the rated voltage. Within the scope of this regulation, the rated voltage is the voltage which is declared by the manufacturer or the voltage at which the equipment is designed to operate.
The test voltage frequency corresponding to the AC voltage shall be between 49 Hz and 51 Hz.
b) Other power supplies
Where the measuring device uses other (primary or secondary) power supplies or batteries, the supply voltage for testing shall be declared by the manufacturer and shall be accepted by the testing laboratories. These values are included in the test report.
3.1.1.2. General requirements for power supply for testing
The equipment shall be tested using the suitable power supply as specified in 3.1.1.2.1 or 3.1.1.2.2. Where the equipment under test can use both external or internal power supplies, the external power supply shall be used to test the equipment and the test shall be then repeated using the internal power supply.
3.1.1.2.1. External power supply for testing
During the test, the power supply of the equipment shall be replaced by an external power supply capable of providing the normal test voltage. The internal impedance of the external power supply for testing shall be sufficiently low and controlled so as not to affect the test results. In this test, the voltage of the external power supply for testing shall be measured at the inputs of the equipment. External power supplies for testing shall be suitably segregated and performed as battery terminals in the equipment. For radiation tests, external supplies shall be arranged to have a minimal effect on the tests.
During the test, the tolerance of the supply voltage shall be within ±1 % of the voltage at the beginning of each test. Reducing the voltage tolerance will reduce the test error.
3.1.1.2.2. Internal power supply for testing
For radiated measurements on portable stations with integral antennas, the equipment shall use a fully charged battery. Batteries shall be provided or as recommended by the manufacturer. If an internal power supply is used, the tolerance of the supply voltage after the test shall be within ±5 % of the voltage at the beginning of each test. If the above requirement is not met, this value shall be included in the test report.
In the case of a fixed test site, an external power supply may replace the internal battery provided or recommended by the manufacturer. This information shall be included in the test report.
3.1.2 Selection of equipment for testing
For individual equipment, the test shall be carried out including the ancillary equipment. If the equipment has some optional functions, but does not affect the RF parameters, the tests need only to be performed on the equipment configured with that combination of features considered to be the most.
3.1.3. Interpretation of measurement results
The interpretation of the results in the test report described in this regulation is specified as follows:
1) The measured value is compared with the corresponding limit to decide whether the equipment meets the requirements of the regulation;
2) The measurement uncertainty of each measurement parameter shall be shown in the test report;
3) The value of the measurement uncertainty reported for each test shall be equal to or less than the values specified in Table 7.
For the method of measurement stated in this regulation, the uncertainty shall be calculated in accordance with the instructions in TR 100 028 and corresponding to the expansion factor (coverage factor) k = 1.96 or k = 2 (the allowable confidence intervals shall be 95 % and 95.45 % respectively where the actual distribution of measurement errors is a normal (Gaussian) distribution).
The specific expansion factor used to calculate the measurement uncertainty shall be specified.
Table 7 - Maximum measurement uncertainties
Parameter | Maximum measurement uncertainty |
Radio frequency RF | ±1 X 10-7 |
Radiated RF power ( ≤ 40 GHz) | ±6 dB |
Radiated RF power (40 GHz to 66 GHz) | ±8 dB |
Radiated RF power (66 GHz to 100 GHz) | ±10 dB (See Note 1) |
Radiated RF power ( >100 GHz) | See Note 2 |
Temperature | ±1°C |
Humidity | ±5 % |
DC and low frequency voltages | ±3 % |
NOTE 1: The achieved sensitivity and measurement uncertainty are a direct result of the chosen test suites. The values mentioned together with the concerns should therefore be considered illustrational rather than absolute for measurements above 66 GHz, given the absence of some relevant information. For radiated emissions above 66 GHz the given measurement uncertainties are based on the assumption of the deployment of a cable based measurement set-up. In the cases of other measurement set-up (e.g. wave guides) it may not be possible to reduce measurement uncertainty to the levels specified in this table. NOTE 2: For measurements above 100 GHz, the measurement uncertainty shall also be included in the test report and a detailed calculation be added. |
3.1.4. Tests in the frequency band above 110 GHz
For measurements above 110 GHz, the "standard" measuring devices is only available in the frequency range of about 110 GHz with a sensitivity limit related to the measurement bandwidth (BW) and the detector. For higher frequencies above 110 GHz, the sensitivity will decrease.
The commercially available calibration capabilities are currently limited to about 110 GHz. Therefore, the measurement results above 110 GHz by different laboratories are not completely comparable because the measuring device is not calibrated at the required operating frequency range.
3.2. Test on transmitters
3.2.1. RF output power measurement
The RF output power, subject to the conditions as stated in 3.1.1, is measured using the test site as described in B.2 of Appendix B and recorded in the measurement method. All equipment under test shall be set to center frequencies within the specified frequency bands.
Step 1:
a) Using suitable attenuators, the measuring device shall be coupled to a suitable diode detector or equivalent device. The output of the diode detector is connected to the y channel of the oscillator or equivalent power measuring device.
b) The combination of diode detector and oscilloscope shall be able to display the duty cycle of the transmitter output signal.
c) The observed duty cycle (Tx_on/(Tx_on + Tx_off)) is denoted by x (0 < x ≤ 1) and shall be included in the test report. For test purposes, the equipment shall operate with a duty cycle equal to or greater than 0.1.
Step 2:
a) The RF output power of the transmitter when operating at a maximum power shall be measured using a spectrum analyser with an integration factor greater than or equal to 5 times of the transmitter repetition interval. Using the mean RMS detection mode, the observed value shall be recorded as “A” (dBm).
b) The EIRP value is calculated from the power A (dBm) measured above and the observed duty cycle is x, according to the formula below.
c) PD = A + 10 x log10 (1/x).
3.2.2. Measurement of permitted operating frequency range
3.2.2.1. Measurement methods
The measurement methods shall be included in the test report.
Measurement methods for equipment using FHSS modulation are given in 3.2.2.2.
The following measurements shall be used respectively for the transmitter frequency ranges and the measured value shall be included in the test report. Where applicable, the measurement of test data sequences shall be applied in accordance with B.1 and B.1.1 of Appendix B.
The transmitter power shall be set to the maximum power level.
The test procedure shall be performed as follows:
a) Set the spectrum analyser to medium display with a minimum sweep of 50.
b) Select the lowest operating frequency of the equipment under test and activate the transmitter in a modulation mode. The RF emissions of the equipment shall be displayed on the spectrum analyser.
c) Use the marker of the spectrum analyser, find a frequency below the lowest operating frequency at which the power spectral density falls below the value given in 2.1.2. This frequency shall be included in the test report.
d) Select the highest operating frequency of the equipment under test and find the highest frequency at which the power spectral density falls below the value given in 2.1.2. This frequency shall be included in the test report.
e) The difference of the frequencies measured in steps c) and d) is the operating frequency range. This value shall be included in the test report.
This measurement shall be repeated for each frequency range as declared by the manufacturer.
3.2.3.2. Measurement method for devices using FHSS modulation
The following measurements shall be used respectively for the transmitter frequency ranges and the measured value shall be included in the test report.
During the tests, the test data sequences are used as specified in B.1 of Appendix B. The transmitter power level shall be set to the rated power level.
The test procedures shall be performed as follows:
a) Set the spectrum analyser to medium display with a minimum sweep of 50.
b) Select the lowest hopping frequency of the equipment under test and activate the transmitter in a modulation mode.
c) Find a frequency below the lowest operating frequency at which the power spectral density falls below the value specified in 2.1.2. This frequency shall be included in the test report.
d) Select the highest hopping frequency of the equipment under test and find the highest frequency at which the power spectral density falls below the value specified in 2.1.2. This frequency shall be included in the test report.
e) The difference of the frequencies measured in steps c) and d) is the operating frequency range of the equipment. This value shall be included in the test report.
This measurement shall be repeated for each frequency range as declared by the manufacturer.
3.2.3. Measurement of out-of-band emissions
The measuring receiver is a voltmeter or spectrum analyser. The bandwidth of the measuring receiver shall be set as specified in CISPR 16. To achieve the required sensitivity, it may be necessary to use a narrower measurement bandwidth, which shall be included in the test report.
The settings for the spectrum analyser are as follows:
- Resolution Bandwidth (RBW): See Table 8.
- Video Bandwidth (VBW) ≥ 3 MHz.
- Detector Mode: RMS/Hz averaged over a period of at least one signal cycle (up to 100 ms)
The frequency spectrum measured at the spectrum analyser shall be recorded in the relative amplitude range of 35 dB. No measurement is required when the mean power spectral density is below -40 dBm/MHz (e.i.r.p.).
The bandwidth of the measuring receiver shall be less than the maximum value shown in Table 8.
Table 8 - Measurement bandwidth
Measurement frequency | Maximum measurement bandwidth |
f < 1 000 MHz | 100 kHz to 120 kHz |
f ³ 1 000 MHz | 1 MHz |
The test site is selected as shown in Annex A, which makes full use of the frequency ranges that meet the specific requirements. The measurement methods are described in Appendix C. The bandwidths of the measuring receiver shall be set to an appropriate value for accurate measurement of unwanted emissions. This bandwidth shall be included in the test report.
For frequencies above 40 GHz, a frequency reducer is used as shown in Figure 2. An internal oscillator is used to reduce the received signal frequency with phase noise better than -80 dBc/Hz at 100 kHz offset. The frequency of the internal oscillator is chosen so that the signal received after the frequency reduction is within the operating frequency band of the spectrum analyser, while maintaining adequate IF response bandwidth to receive the entire frequency spectrum of the signal. The e.i.r.p. of the EUT shall be measured and recorded.
Figure 2 - Diagram of test setup of out-of-band radiation for the frequency band above 40 GHz
Out-of-band emissions of the signal in the normal modulation mode shall be measured and recorded over the frequency range adjacent to the operating frequency range specified in Table 1, up to a frequency at which the emission level is less than 50 dB relative to the maximum emission level.
3.2.4. Measurement of spurious emissions
This measurement method is applicable to transmitters with integral antennas.
a) In this measurement the full use of the specified frequency ranges shall be required.
Initially, the test antenna is vertically polarized and connected to the measuring receiver, through a suitable filter to avoid overload of the measuring receiver if necessary. The bandwidth of the measuring receiver shall be adjusted to such an extent that its receive sensitivity is 6 dB below the unwanted emission limits shown in Table 3, clause 2.1.3.2. This bandwidth shall be included in the test report.
To measure spurious radiation below the 2nd harmonic of the carrier frequency, a notch filter (“Q” notch filter) centered at the carrier frequency, with a signal loss of at least 30 dB, should be used.
Transmitters under test shall be mounted on a stand in the reference position and shall be left in the nonmodulation mode (see B.1 of Appendix B). If the modulation cannot be stopped and the test must then be performed in the modulation mode, this shall be included in the test report.
b) The measuring receiver shall be adjusted between 30 MHz and 2,2 times of the carrier frequency, except for the channels on which the transmitter is intended to operate. The frequency of each identified unwanted emission shall be recorded. If the test sites are subject to external interference, widen the display and reduce the distance between the transmitter and the test antenna to find a good value.
c) At each frequency at which an emission occurs, the measuring receiver shall be adjusted and the test antenna shall be raised or lowered through the specified height limit until a maximum signal level is reached on the measuring receiver.
d) The transmitters are rotated in 360° around the vertical axis, to maximize the received signals.
e) The test antennas are raised or lowered again through the specified range of heights up to the received maximum level. This level will be recorded.
f) At each frequency at which an emission occurs, the signal generators, replacement antenna and measuring receiver shall be adjusted. The test antenna is raised or lowered within the specified height until the maximum signal level is reached on the measuring receiver. The level of the signal generator for the analog signal level on the measuring receiver as stated in e) shall be recorded. After further correction for the replacement antenna gain and cable loss between the signal generators and the replacement antenna, this is an unwanted emission at this frequency.
g) The frequencies and levels of each measured emission and the bandwidth of the measuring receiver shall be included in the test report.
h) Steps c) to g) shall be repeated with the test antenna that is horizontally polarized
i) If the power adjustment feature is used, the test steps from c) to h) shall be repeated at the lowest power level.
j) Steps c) to h) shall be repeated with the transmitter in the standby condition if this option is available.
The sensitivity of the spectrum analyser shown to background noise is at least 6 dB above the limit given in Table 5. To improve the sensitivity of the measuring receiver, the measurement bandwidth or measuring distance may be reduced. If this is not done, background noise during the test shall be included in the test report.
As recommended in Clause 3 of CEPT/ERC 74-01, spurious emission domain limits are applied to the frequency range from 9 kHz to 300 GHz. However, subject to the conditions, the frequency ranges of spurious emission measurements may be limited, ensuring that the limits are met. Refer to Clause 3 of CEPT/ERC recommendation 74-01 for further guidance.
NOTE: Testing at higher frequencies may not determine measurement uncertainties due to the lack of key references. In addition, further simplification of the test technique saves time/cost, while it is possible to ensure the fulfilment of the requirements.
3.3. Test on receivers
This measurement method is applicable to transmitters with integral antennas.
a) In this measurement, the full use of the test site of the specified frequency ranges shall be required.
Initially, the test antenna is vertically polarized and connected to the measuring receiver, through a suitable filter to avoid overload of the measuring receiver if necessary. The bandwidth of the measuring receiver shall be adjusted until the sensitivity of the measuring receiver is at least 6 dB below the unwanted emission limit specified in clause 3.2.3. This bandwidth shall be included in the test report.
The test equipment shall be placed on a stand in the standard position.
b) The measuring receiver shall be adjusted between 30 MHz and 2.2 times of the carrier frequency. The frequency of each detected unwanted emission will be recorded. If the test sites are subject to external interference to find a good value, expand the display and reduce the distance between the transmitter and the test antenna.
c) At each frequency at which a component occurs, the measuring receiver shall be adjusted and the test antenna shall be raised or lowered through the specified height limit until a maximum signal level is reached on the measuring receiver.
d) The receivers are rotated in 360° around the vertical axis, to maximize the received signals.
e) The test antennas are raised or lowered again through the specified range of heights up to the maximum level received. This level will be recorded.
f) At each frequency at which a component is detected, the transmitters, replacement antennas and measuring receivers shall be adjusted. The test antenna is raised or lowered through the specified range of heights until the maximum signal level is reached on the measuring receiver. The level of the signal generator for the analog signal level on the measuring receiver as stated in e) shall be included. After further correction for the replacement antenna gain and the cable loss between the transmitters and the replacement antenna, these values represent unwanted radiation components at this frequency.
g) The frequencies and levels of each measured emission and the bandwidth of the measuring receiver shall be included in the test report.
h) Measurements from c) to g) shall be repeated with the test antenna that is horizontally polarized.
As recommended in Clause 3 of CEPT/ERC 74-01, the spurious emission domain limits of the radio equipment considered herein are applied to the frequency range up to 300 GHz. However, for practical measurements only, the frequency ranges of spurious emission measurements may be limited. For further guidance, refer to Clause 3 of CEPT/ERC 74-01.
4. REQUIREMENTS FOR MANAGEMENT
4.1. General short-range devices within the scope specified in Article 1.1 shall comply with the provisions of this regulation.
4.2. The test of technical specifications in this regulation in order to provide conformity certification and announcement shall comply with the applicable regulations. Organizations and individuals are allowed to use measurement/ test results of designated domestic testing laboratories, or recognized foreign testing laboratories or accredited domestic and foreign laboratories in accordance with ISO/IEC 17025, or the manufacturer's measurement/test results.
5. RESPONSIBILITIES OF ORGANIZATIONS AND INDIVIDUALS
The relevant organizations and individuals shall comply with the provisions on conformity certification and announcement of equipment within the scope of this regulation and subject to inspection by the State authorities in accordance with the applicable regulations.
6. ORGANIZATION OF IMPLEMENTATION
6.1. The Authority of Telecommunications, the Department of Radio Frequency and the Departments of Information and Communications shall organize the implementation, guidance and management of equipment under the scope of this regulation.
6.2. Where the provisions mentioned in this regulation are changed, supplemented or replaced, the provisions of the new document shall apply.
6.3. During the implementation of this Regulation, if any problem arises, relevant organizations and individuals shall report it in writing to the Ministry of Information and Communications (Department of Science and Technology) for guidance and settlement./.
Appendix A
(Normative)
Radiation measurements
A.1. Replacement measurement
The replacement measurement can be used without guaranteeing the suitability of the test site, since the error of the measurement site at certain frequencies will be constant and can be offset through the replacement measurement. The accuracy of the measurement depends mainly on the accuracy of the RF transmit parameters and the gain value of the replacement antenna.
A.1.1. Principle of replacement measurement
When the radiated power is evaluated by the replacement measurement, the peak power will be calculated.
The use of the error evaluation method of “test site comparison” reduces the measurement uncertainty value. The disadvantage of this method increases the measurement period since many parameters must be determined for an EUT.
A suitable description of “test site comparison” is shown in Figure A.1. Figure A.1 includes: an antenna without power absorption parameters (1) providing a sufficiently wide opening angle, with a height-adjustable support (2), an antenna cable (3) and a display unit that is a measuring receiver or spectrum analyser or a power meter (4).
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