Road vehicles-Component test methods for electrical/electronic disturbances from narrowband radiated electromagnetic energy- Part 3:Transverse electromagnetic(TEM)cell
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GB/T 33014 consists of the following parts under the general title Road vehicles - Component test methods for electrical/electronic disturbances from narrowband radiated electromagnetic energy:
——Part 1: General;
——Part 2: Absorber-lined shielded enclosure;
——Part 3: Transverse electromagnetic (TEM) cell;
——Part 4: Bulk current injection (BCI);
——Part 5: Stripline;
——Part 7: Direct radio frequency (RF) power injection;
——Part 8: Immunity to magnetic fields;
——Part 9: Portable transmitters;
——Part 10: Immunity to conducted disturbances in the extended audio frequency range;
——Part 11: Reverberation chamber.
This part is Part 3 of GB/T 33014.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part has been redrafted and modified in relation to ISO 11452-3: 2001, Road vehicles - Component test methods for electrical disturbances from narrowband radiated electromagnetic energy - Part 3: Transverse electromagnetic (TEM) cell.
The technical deviations between this part and ISO 11452-3: 2001 and their justifications are as follows:
——Clause 1 is normatively prepared in accordance with GB/T 1.1-2009;
——ISO 11452-1 referenced is changed to GB/T 33014.1 modified in relation to ISO 11452-1;
——“AN, see Annex C for a schematic” using CISPR25 in the original international standard is changed to GB/T 33014.2, which is equivalent to the former in contents. As well as GB/T 33014.2 is added in the “Normative references”;
——in order to realize the consistency with Part 1 in the understanding and representation method, I, II, III, IV, V given in Table C.1 are changed to L1, L2, etc., and I, II, III, etc. are understood as statues I, II, III, etc.;
——Equation (B.2) in original international standard is revised due to some wrong.
The following editorial change has been made in this part:
——the foreword, introduction and bibliography of the original international standard is deleted.
This part was proposed by the Ministry of Industry and Information Technology of the People's Republic of China.
This part is under the jurisdiction of the National Technical Committee of Auto Standardization (SAC/TC 114).
Road vehicles - Component test methods for electrical/electronic disturbances from narrowband radiated electromagnetic energy - Part 3: Transverse electromagnetic (TEM) cell
1 Scope
This part of GB/T 33014 specifies the component test methods for electrical/electronic disturbances from narrowband radiated electromagnetic energy with transverse electromagnetic (TEM) cell
This part is applicable to electrical/electronic components for Categories M, N, O and L vehicles, regardless of the vehicle propulsion system, (e.g. spark-ignition engine, diesel engine, electric motor).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 33014.1 Road vehicles - Component test methods for electrical/electronic disturbances from narrowband radiated electromagnetic energy - Part 1: General (GB/T 33014.1-2016, ISO 11452-1: 2005, MOD)
GB/T 33014.2 Road vehicles - Component test methods for electrical/electronic disturbances from narrowband radiated electromagnetic energy - Part 2: Absorber-lined shielded enclosure (GB/T 33014.2-2016, ISO 11452-2: 2004, MOD)
3 Terms and definitions
For the purpose of this document, the terms and definitions given in GB/T 33014.1 apply.
4 Test conditions
The applicable frequency range of transverse electromagnetic (TEM) cell is 0.01 MHz to 200 MHz. The upper frequency range limit of the TEM cell is a direct function of the TEM cell dimensions. See Annex A for suggested TEM cell dimensions and Annex B for calculations and measurements of TEM-cell frequency range.
The users shall specify the test severity level(s) over the frequency range. See Annex D for suggested test severity levels.
The following standard test conditions shall meet the requirements of GB/T 33014.1:
——test temperature;
——test voltage;
——modulation;
——dwell time;
——frequency step sizes;
——definition of test severity levels;
——test signal quality.
5 Test apparatus
5.1 TEM cell
The TEM cell used for this test is a rectangular coaxial line with a 50 Ω characteristic impedance (see Figure 1). The device (DUT) under test is exposed to a uniform TEM field.
The TEM cell is a laboratory measurement system which can be used to generate test fields within 2 dB of the theoretical value if the device under test does not occupy an excessive portion of the test volume (see 5.3).
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Key:
1——outer conductor (shield);
2——septum (inner conductor);
3——access door;
4——connector panel (optional);
5——coaxial connectors;
6——dielectric support;
7——DUT;
8——input/output leads
Figure 1 TEM cell
5.2 Instrumentation
Figure 2 shows an example of a TEM cell test set-up. The TEM cell has high resonances in the region greater than the suggested upper frequency limit. A low pass filter with an attenuation of at least 60 dB at frequencies above 1.5 times the cut-off frequency of the TEM cell (see Annex C) shall be installed to avoid resonances (e.g. 200 MHz TEM cell: 60 dB for frequencies above 300 MHz).
Key:
1——signal generator;
2——broadband amplifier;
3——low-pass filter;
4——dual-directional coupler (30 dB decoupling ratio minimum);
5——RF-power meter;
6——peripheral;
7——DUT;
8——dielectric support;
9——low pass filters/connector panel;
10——coupler;
11——high power load (50Ω);
12——controller;
13——TEM cell.
a Preflected (reflected power);
b Pforward (forward power);
c Poutput (output power).
Figure 2 Example TEM cell configuration
5.3 Test set-up
5.3.1 General
In order to maintain the homogeneous field in the TEM cell and obtain reproducible measurement results, DUT shall be no larger than one-sixth of the cell (inside) height, b. The DUT shall be placed in the center of the cell on a dielectric equipment support (εr≤1.4).
The DUT and the wiring harness may be positioned in either of two arrangements, depending on whether the exposure of the DUT and the wiring harness (5.3.2) or that of the DUT alone is being tested.
5.3.2 Exposure of DUT and wiring harness (for major field coupling to the harness)
The height of the dielectric support is one sixth of cell height b (see Figure 3). In order to obtain reproducible measurement results, the DUT together with its wiring harness or printed circuit board shall be placed in the same position in the TEM cell for each measurement. In addition to the direct RF-field coupling to the device under test, the use of an unshielded harness or printed circuit board will result in a common mode electrical field coupling and a differential mode magnetic field coupling, depending on the inclination and the width of the harness or circuit board.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Test conditions
5 Test apparatus
6 Test
Annex A (Informative) TEM cell dimensions
Annex B (Informative) Calculations and measurements of TEM-cell frequency range
Annex C (Informative) Installation of external components and low pass filter design
Annex D (informative) Function performance status classification (FPSC)
