GB/T 38889-2020 PDF in English
GB/T 38889-2020 (GB/T38889-2020, GBT 38889-2020, GBT38889-2020)
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Name of Chinese Standard | Status |
| GB/T 38889-2020 | English | 345 |
Add to Cart
|
0-9 seconds. Auto-delivery.
|
Antennas and reception systems for radio interference -- Antenna measurement -- Vehicle antennas and system
| Valid |
Standards related to (historical): GB/T 38889-2020
PDF Preview
GB/T 38889-2020: PDF in English (GBT 38889-2020) GB/T 38889-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 33.100
L 06
Antennas and Reception Systems for Radio
Interference - Antenna Measurement - Vehicle
Antennas and System
ISSUED ON: JUNE 2, 2020
IMPLEMENTED ON: DECEMBER 1, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative References ... 4
3 Terms, Definitions and Abbreviations ... 4
4 Measurement Parameters ... 7
5 Measurement of AM / FM Receiving Antenna ... 14
6 Measurement of Navigation Antenna ... 18
7 Measurement of Vehicle-mounted Millimeter-wave Radar Antenna ... 23
8 Measurement of Digital Broadcasting Antenna ... 33
9 Measurement of Keyless Antenna ... 34
10 Measurement Report ... 34
Appendix A (normative) Requirements for Measurement Site ... 36
Appendix B (informative) Classical Probe Compensation in Near Field - Far
Field Conversion ... 39
Bibliography ... 41
Antennas and Reception Systems for Radio
Interference - Antenna Measurement - Vehicle
Antennas and System
1 Scope
This Standard stipulates the measurement requirements and measurement
procedures of radiation characteristics and OTA characteristics of vehicle antenna
under complete-vehicle conditions. It includes the requirements for measurement
environment and measurement site; antenna pattern; the measurement procedures of
reception sensitivity, and power reception and transmission.
This Standard is applicable to the measurement of AM / FM receiving antenna,
navigation antenna, vehicle-mounted millimeter wave radar antenna, digital
broadcasting antenna, satellite digital broadcasting antenna and keyless antenna in
vehicle antenna. Other types of antennas may also be measured with reference to the
stipulations of this Standard.
2 Normative References
The following documents are indispensable to the application of this document. In
terms of references with a specified date, only versions with a specified date are
applicable to this document. In terms of references without a specified date, the latest
version (including all the modifications) is applicable to this document.
GB/T 14733.10-2008 Terminology for Telecommunication - Antenna
GB/T 26256-2010 Interference, Coexistence and Corresponding Measurement
Methods of 2.4 GHz Wireless Telecommunications Equipment
YD/T 2193-2010 Measurement Method for Radiated RF (radio frequency) Power and
Receiver Performance of WLAN Devices
YD/T 2868-2015 Testing Methods of Passive Antennas in Mobile Communication
System
IEEE 145-2013 IEEE Standard for Definitions of Terms for Antennas
3 Terms, Definitions and Abbreviations
3.1 Terms and Definitions
What is defined in GB/T 14733.10-2008, GB/T 26256-2010, YD/T 2193-2010, YD/T
2868-2015 and IEEE 145-2013, and the following terms and definitions are applicable
to this document.
3.1.1 Antenna
Antenna refers to a device that can effectively radiate or receive radio waves from the
space.
NOTE 1: the term antenna is sometimes used for electromagnetic equipment, whose
coupling distance is less than the distance associated with the radiation field.
NOTE 2: antenna provides the required coupling between the transmitter or receiver and
the medium that transmits the radio waves.
3.1.2 Vehicle antenna
Vehicle antenna refers to a device that is installed on a vehicle to complete the function
of radiating or receiving radio waves in a radio transmission and reception system.
3.1.3 Passive antenna
Passive antenna refers to antenna that does not carry any active devices.
[Definition 4, IEEE 145-2013]
3.1.4 Active antenna
Active antenna refers to antenna packaged together with active devices (for example,
amplifier or impedance matching electronics).
[Definition 4, IEEE 145-2013]
3.1.5 Active antenna system
Active antenna system refers to an antenna system that integrates antenna transceiver
module, low noise amplifier module, power supply module and active impedance
matching resistance, etc.
3.1.6 Gain
Gain refers to the ratio of power density of the signal generated by the actual antenna
and the ideal radiating unit in the same point in space under the condition of equal
input power.
NOTE 1: the unit of gain is dBi;
NOTE 2: gain does not include the loss caused by impedance and polarization mismatch,
and does not depend on the system, to which, the antenna is connected.
reception sensitivity of the antenna near the H plane.
3.1.13 Effective isotropic sensitivity
Effective isotropic sensitivity refers to the reception sensitivity value of the terminal
being tested in a certain direction, expressed in the minimum forward link power sent
by the base station in this direction that can be received by the terminal being tested.
This power value is the result obtained through the comparison with the omnidirectional
antenna (0 dBi gain).
3.1.14 Antenna radiation diameter
Antenna radiation diameter refers to the minimum spherical diameter surrounding the
radiating part of the antenna.
NOTE: the minimum sphere contains all antenna supporting structures that would affect
the radiation pattern.
3.2 Abbreviations
The following abbreviations are applicable to this document.
EIRP: Effective Isotropic Radiated Power
EIS: Effective Isotropic Sensitivity
GNSS: Global Navigation Satellite Systems
HP: Horizontal Polarization
NHPIS: Near-horizon Partial Isotropic Sensitivity
NHPRP: Near-horizontal Partial Radiated Power
OTA: Over The Air
TIS: Total Isotropic Sensitivity
TRP: Total Radiated Power
VP: Vertical Polarization
4 Measurement Parameters
4.1 Overview
d) The wireless communication comprehensive tester is used to simulate the
establishment of a connection between the base station and the antenna
being tested; it is also used to measure the reception sensitivity;
e) The switch conversion unit is used to switch different paths among the various
measurements;
f) The control equipment is used for measurement software and the
measurement work of the entire measurement system.
4.3.3 TRP measurement
4.3.3.1 TRP measurement method
In the measurement of TRP, by measuring EIRP at different spherical positions around
the antenna being tested, the radiofrequency radiation performance of the antenna is
measured. Each frequency band is measured at the maximum transmission power.
The measurement method of TRP includes:
a) The wireless communication comprehensive tester establishes
communication links with the antenna being tested through communication
antenna.
b) The measuring probe transmits the measurement data to the spectrum
analyzer or the power meter through the measurement path for signal analysis.
The schematic diagram of the connection of the measurement system is
shown in Figure 2.
c) Rotate the rotary table; on the Theta () axis and the Phi () axis of the
spherical coordinates, respectively measure the effective radiated power
EIRP of each point in the three-dimensional space.
d) TRP is calculated through the measured EIRP and Formula (1):
Where,
M---number of measurement points on the Phi () axis;
N---number of measurement points on the Theta () axis.
5 Measurement of AM / FM Receiving Antenna
5.1 Measurement Requirements
5.1.1 Measurement environment
The antenna being tested shall be working under the following environment:
---Temperature: -40 °C ~ + 70 °C;
---Relative humidity: 20% ~ 75%.
5.1.2 Measurement site
The frequency modulation broadcasting frequency band of the AM / FM receiving
antenna is 87 MHz ~ 108 MHz. In addition, a larger volume of the vehicle signifies a
larger required space for the measurement environment. Hence, the measurement of
the AM / FM pattern shall be performed in the open field.
5.2 AM / FM Receiving Antenna Pattern Measurement
5.2.1 Measurement equipment
5.2.1.1 Rotary table
The rotary table can implement 360° rotation.
5.2.1.2 Antenna
The antennas used for the AM / FM receiving antenna pattern measurement include:
---Reference antenna: antenna used for zero calibration measurement. Dipole
antenna, which has uniformly distributed patterns, shall be used.
---Transmitting antenna: directional antenna whose frequency band covers the
frequency band of the antenna being tested; the cross-polar isolation of the
antenna is less than 30 dB.
5.2.1.3 Basic requirements
The measurement equipment and instruments (for example, signal generator, receiver
or vector network analyzer) used for the measurement shall have good stability,
reliability, dynamic range and measurement accuracy. The instruments shall have a
sweep frequency working mode; the available frequency range of the instruments shall
cover the measurement frequency.
5.2.1.4 Signal generator
The signal generator shall satisfy:
---Frequency accuracy: ± 0.3 % ~ ± 0.43%;
---Spectrum purity: harmonic < -20 dBc; non-harmonic < -50 dBc;
---Output power: 0 dBm ~ 30 dBm.
5.2.1.5 Receiver
The receiver shall satisfy:
---Sensitivity: -110 dBm ~ -80 dBm;
---Dynamic range: > 50 dB;
---Frequency accuracy: ± 5 10-6.
5.2.1.6 Signal amplifier
It shall be ensured that the signal amplifier can reach a certain power.
5.2.1.7 Vector network analyzer
The vector network analyzer shall satisfy:
---Resolution: 1 Hz;
---Frequency accuracy: ± 5 10-6;
---Signal source output power: -55 dBm ~ 10 dBm;
---Dynamic range: 130 dB;
---Measurement bandwidth: 1 Hz ~ 30 kHz.
The vector network analyzer may replace the receiver and the signal generator.
5.2.2 Measurement procedures
5.2.2.1 Zero calibration of reference antenna
When performing zero calibration of the reference antenna, both the vertical and
horizontal polarization directions shall receive zero calibration. See the main
procedures below:
a) The complete-vehicle is located outside the measurement field, and the
reference antenna is placed in the middle of the rotary table;
b) The reference antenna is connected to the input end of the receiver; the
the following characteristics:
a) The gain of the antenna shall be accurate and already-known;
b) The structure of the antenna shall be simple and firm;
c) The antenna shall be linearly polarized;
d) The gain of the standard gain antenna shall be determined in accordance with
the gain of the antenna being tested; in near-field measurement, the gains of
the two should be relatively close to each other.
6.2.3 Measurement procedures
6.2.3.1 Zero calibration of standard gain antenna
When performing zero calibration of standard gain antenna, the main procedures are
as follows:
a) Set up the standard gain antenna on the rotary table; determine the minimum
envelope radius Rmin of the standard gain antenna;
b) In accordance with the schematic diagram of calibration layout, connect the
radiofrequency cable, as it is shown in Figure 8;
c) Set up the measurement frequency, power and intermediate frequency
bandwidth of the signal source and vector receiver;
d) Set up the scanning range and sampling interval of the , and angle;
e) The dual-polarization measurement probe implements the scanning of the
and angle; the azimuth angle of the standard gain antenna is continuously
moved to implement the scanning of the angle; the vector receiver collects
the phase value of the measured signal amplitude, and records it as (Etheta/phi),
expressed in [dB/(°)];
f) The receiver collects the phase value of the measured signal amplitude, and
records it as (Etheta/phi), expressed in [dB/(°)].
The measurement environment shall satisfy the general requirements in 5.1.1.
7.1.2 Measurement site
The measurement site shall satisfy the general requirements in Appendix A.
7.1.3 Power supply
During AC power switching power supply, the voltage floats ± 10% on the basis of the
normal power supply voltage, or, configurate an interruptible power supply.
7.2 Vehicle-mounted Millimeter Wave Radar Antenna Pattern
Measurement
7.2.1 General
When conducting vehicle-mounted millimeter wave radar antenna pattern or OTA
measurement, the millimeter wave radar antenna system shall be measured under
simulated loading conditions.
The vehicle-mounted millimeter wave radar antenna pattern may adopt two methods
for measurement: cylindrical near-field or spherical near-field. The measurement
system includes mechanical scanning system, radiofrequency subsystem, control
subsystem and measurement software.
Cylindrical near-field and spherical near-field measurements are mainly different in the
mechanical scanning system and the algorithm of the measurement software.
7.2.2 Cylindrical near-field measurement method
7.2.2.1 Cylindrical near-field mechanical scanning system
Cylindrical near-field mechanical scanning system collects data on a cylindrical surface.
The probe is installed on a linear guide in the Z axis direction. The antenna being tested
is installed on the azimuth rotary table in -direction rotation in the coordinate system,
as it is shown in Figure 10.
The requirements for the radiofrequency subsystem, control subsystem, measurement
software and standard gain antenna are shown in 6.2.2.
sampling criterion.
7.2.3.4 Scanning area
If scanning on a complete sphere, there will be no truncation error. However, it is often
difficult to implement scanning within the 4 solid angle corresponding to the entire
spherical surface, which will generate truncation errors. The corresponding far field is
merely effective within a certain range, the far-field effective angular field is determined
through Formula (19):
Where,
r0---the smallest spherical radius surrounding the antenna being tested, expressed in
(m);
Rm---the measurement ball radius, expressed in (m);
NF±---the angular range covered by the near-field scan.
7.2.3.5 Spherical near-field measurement procedure
Conduct the measurement in accordance with 6.2.3. If the frequency band 77 GHz is
measured, spectrum-spreading equipment shall be used.
7.2.4 Measurement result
With reference to Appendix B, in accordance with the original data of the test antenna
measured by the instrument, perform cylindrical or spherical near field - far field
conversion, so as to obtain the far-field pattern of the antenna being tested. Then,
process it and obtain the beam width, beam pointing and cross-polarization. Ina
accordance with the data of the calibration antenna, calculate the gain of the antenna
being tested.
7.3 OTA Measurement of Vehicle-mounted Millimeter Wave Radar Antenna
When performing OTA performance measurement of vehicle-mounted millimeter wave
radar antenna, in accordance with 4.3.3, conduct TRP or NHPRP measurement.
8 Measurement of Digital Broadcasting Antenna
8.1 Measurement of Satellite Digital Broadcasting Antenna Pattern
Since digital broadcasting antenna has the same radiation characteristics as AM / FM
antenna, its pattern may be measured in accordance with 5.4.
8.2 OTA Measurement of Satellite Digital Broadcasting Antenna
When performing OTA measurement of satellite digital broadcasting antenna, TIS or
NHPIS measurement may be conducted in accordance with 4.3.4.
9 Measurement of Keyless Antenna
9.1 Measurement of Keyless Antenna Pattern
Since keyless antenna has the same radiation characteristics as AM / FM antenna, its
pattern may be measured in accordance with 5.2.2.
9.2 OTA Measurement of Keyless Antenna
When performing OTA performance measurement of keyless antenna, TRP or NHPRP
measurement may be conducted in accordance with 4.3.3, or, TIS or NHPIS
measurement may be conducted in accordance with 4.3.4.
10 Measurement Report
Measurement result shall be recorded in a comprehensive measurement report. Table
2 provides a summary list of all required items. The measurement report shall have the
following details, so as to provide measurement repeatability:
a) General information, which includes:
1) General information shall include the location of measurement and the
responsible (someone who can undertake the due responsibilities) owner,
etc.;
2) If site confirmation is performed by another party or organization, the
party or organization’s information shall be provided;
3) Modes of drawings, photos and part numbers shall be used to describe
the configuration of measurement, including the auxiliary equipment;
4) In addition, the date of measurement shall be provided; on the cover of
the report, there shall also be the name and signature of the author and
authorizer of the report.
b) In terms of the evaluation of the validity period and restrictions: before
measuring vehicle antenna, the validity period of the site shall be proved;
special environmental conditions, configuration conditions or restrictions shall
be clearly declared.
c) Measurement layout, which includes:
Appendix A
(normative)
Requirements for Measurement Site
A.1 Basic Requirements
The measurement of radiation parameters and OTA parameters of vehicle antenna is
required to be performed in an open field or microwave anechoic room. Any site that
can satisfy the open field or microwave anechoic room might become an alternative
test site.
The test site shall satisfy the following requirements:
a) The size of net space shall satisfy the spatial requirements of the
measurement equipment, the installation and setting of the antenna being
tested, and the scanning and sampling;
b) The range of the static scanning zone shall be greater than or equals to the
smallest sphere containing the antenna being tested;
c) When the antenna being tested is moved along the horizontal axis of the static
zone, the fluctuation of the received signals shall not exceed ± 2 dB; when the
antenna being tested is moved up and down, left and right along the same
plane perpendicular to the ground of the static zone, the fluctuation of the
received signals shall not exceed ± 0.3 dB;
d) It shall be ensured that reflections from external objects do not affect the
measurement result.
A.2 Requirements for Open Field
The open field shall satisfy the following requirements:
a) The measurement site shall be an open field without electromagnetic wave
reflectors; avoid buildings, power lines, fences and trees, and keep away from
underground cables and pipes, etc.;
b) If the measurement site uses a climate protective cover, then, the climate
protective cover shall be able to protect the entire test site, including the
antenna being tested and the system; the used materials shall have
radiofrequency transparency, so as to avoid undesired reflections;
c) The measurement site with metal grounding plate should be used; the time
domain method may be used to eliminate ground reflection; the measurement
facilities and personnel shall be beyond the barrier-free area;
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
|