Application of Anoni spectrum analyzer, EMC antenna and near field probe in EMC&EMI pre-test

With the development of electrical and electronic technology, household electrical appliances are becoming more and more popular and electronic, radio and television, postal and telecommunications, and computer networks are becoming more and more developed, and the electromagnetic environment is becoming more and more complex and deteriorating. As a result, the electromagnetic compatibility (EMC, electromagnetic interference, EMI, and electromagnetic resistance to EMS) of electrical and electronic products has also received increasing attention from governments and manufacturers. The electromagnetic compatibility (EMC) of electronic and electrical products is a very important quality indicator. It is not only related to the working reliability and safety of the product itself, but also may affect the normal operation of other equipment and systems, and is related to the protection of the electromagnetic environment. In order to regulate the electromagnetic compatibility of electronic products, all developed countries and some developing countries have formulated electromagnetic compatibility standards. Electromagnetic compatibility standards are the basic requirements for products to work properly in actual electromagnetic environments. The reason why they are called basic requirements is that even if the product meets the electromagnetic compatibility standards, interference problems may occur in actual use. The standards of most countries are based on the standards formulated by the International Electrotechnical Commission (IEC).

The European Community government stipulates that from January 1, 1996, all electrical and electronic products must pass EMC certification and be affixed with the CE mark before they can be sold in the European Community market. This move has caused widespread influence in the world, and governments of various countries have taken measures to implement mandatory management of the EMC performance of electrical and electronic products. Internationally, the more influential ones, such as the EU 2004/108/EC Directive (i.e., the EMC Directive) and the US Federal Code CFR 47/FCC Rules, have put forward clear requirements for electromagnetic compatibility certification.

EMC (Electromagnetic Compatibility) is electromagnetic compatibility, which includes EMI (electromagnetic interference) and EMS (electromagnetic anti-disturbance). EMC is defined as the ability of a device or system to work normally in its electromagnetic environment and not cause unbearable electromagnetic interference to any device or anything in the environment. The whole of EMC is called electromagnetic compatibility. EMP refers to electromagnetic pulse.

EMC = EMI + EMS (EMI: Electromagnetic Interference EMS: Electromagnetic Capacitance)

The National Technical Committee on Radio Interference Standards, the National Technical Committee on Electromagnetic Compatibility Standardization and other standardization groups have developed a series of EMC standards (the same is true in Europe and the United States), such as EMC standards for some major product categories: information technology equipment (ITE); household and commercial equipment; industrial equipment; communications equipment; radio; television receivers and related equipment; traction and transportation equipment; public utility equipment (electricity, gas, water, etc.); medical equipment; measuring and test equipment; equipment connected to medium-voltage and high-voltage public power supply systems.

2. Commonly used typical product standards

GB 4824-2004 "Measurement Methods and Limits of Electromagnetic Disturbance Characteristics of Industrial, Scientific and Medical (ISM) Radio Frequency Equipment" (EN55011); GB 9254-2008 "Limits and Measurement Methods of Radio Disturbance of Information Technology Equipment" (EN55022); GB 4824-2004 "Measurement Methods and Limits of Electromagnetic Disturbance Characteristics of Industrial, Scientific and Medical (ISM) Radio Frequency Equipment" specifies the limits and measurement methods of electromagnetic disturbance characteristics of industrial, scientific and medical (ISM) equipment and electrical discharge machining (EDM) and arc welding equipment; This standard specifies the limits and measurement methods of radio frequency disturbances in the frequency range of 9kHz-400GHz, and is also applicable to industrial, scientific and medical (ISM) lighting equipment operating in the ISM frequency band of 2.45GHz and 5.8GHz. The radio disturbance limits for information technology equipment in GB 9254-2008 "Radio disturbance limits and measurement methods for information technology equipment" are considered to ensure appropriate emission levels to protect radio broadcasting and telecommunications services, and to allow other equipment to operate as required at a reasonable distance; information technology equipment (ITE) may include data processing equipment, office equipment, electronic business equipment, telecommunications equipment, etc. (according to the definition of the ITU Radio Regulations, any equipment with radio transmission and (or) reception functions shall meet national radio regulations, regardless of whether CISPR22 is valid for it).

3. Recommend Anoni products to solve the difficulties of EMC/EMI electromagnetic compatibility and electromagnetic interference testing

The instruments and systems currently available on the market for EMC certification compliance testing are often very expensive, and they also require the establishment of a professional and sophisticated EMC laboratory or a rental laboratory, which has high investment costs and very cumbersome testing steps. Therefore, in order to obtain EMC-related certifications, the development of new products often involves running back and forth between the EMC certification laboratory and the company's R&D department, constantly redesigning, rectifying, and retesting. Companies are troubled by the fact that their products cannot be shipped because the electromagnetic radiation interference intensity exceeds the electromagnetic compatibility standards, or that the system cannot work properly due to electromagnetic interference between circuit modules, thus delaying the launch of the product. Therefore, it is very necessary for engineers to conduct compliance pre-tests during the design period and in the product development stage to ensure that the electromagnetic radiation measurement results of the developed products meet the requirements of electromagnetic radiation regulations and the product launch schedule.

We strongly recommend the use of the EMC/EMI electromagnetic compatibility and electromagnetic interference test solution consisting of the electromagnetic compatibility test spectrum analyzer and related EMC antennas and near-field probe sets originally imported from Germany by AARONIA AG, to quickly find serious EMI interference problems and quickly determine whether the product complies with the corresponding EMC standards, thereby helping engineers determine the best, economical and efficient electromagnetic compatibility and electromagnetic interference rectification plan for the products they are developing.

Anoni's electromagnetic compatibility test spectrum analyzer is very affordable and easy to operate. It provides free test spectrum PC software with rich functions, which is convenient for test comparison and storage of historical test data. The software has built-in various EMC-related standards and restriction standards, which is convenient and simple to judge the existing problems. Anoni's various EMC test receiving antennas are very small in size, with excellent frequency response, and equipped with matching calibration data. They are very affordable and suitable for spectrum analyzers or receivers of various brands. They are the best choice for high-end spectrum analyzer receiving antennas. At present, many KEYSIGHT (formerly Agilent) users choose Anoni's receiving antennas for various tests.

4. Anoni EMC & EMI pre-test equipment configuration and main parameters

1) Host: Electromagnetic compatibility test spectrum analyzer (electromagnetic radiation test spectrum analyzer)

Model: SPECTRAN HF-60105 (with high-precision timing base and 15dB low-noise preamplifier)

Frequency range: 1MHz 9.4GHz (see options to expand to 9KHz-9.4GHz)

Displayed average noise level: -155dBm (1Hz); (-170dBm (1Hz) 15dB preamp on)

Resolution bandwidth: 200Hz - 50MHz

EMC filters: 200Hz, 9kHz, 120kHz, 200kHz, 1,5MHz, 5MHz

Measurement accuracy: +/- 1dB

Data logger: 64K (option 001 can be expanded to 1MB)

2) Far-field antenna: biconical antenna

Model: BicoLOG 20100E

Frequency range: 20MHz-1GHz

Antenna factor see detailed specifications
 

Maximum transmit power: 1W (30dBm or 0dbW)

Impedance: 50 Ohms

Gain: -38dBi to 1dB

Antenna factor: 17-34dB/m

3) Far-field directional antenna: log-periodic antenna

Model: HyperLOG60100

Frequency range: 680MHz-10GHz

Antenna factor see detailed specifications

Maximum transmit power: 100W CW (400MHz)[page]

Impedance: 50 Ohms

VSWR: < 1:2.5

Gain: 5dBi

Antenna factor: 22-46dB/m

4) Near field antenna: Near field probe set

Model: PSB2 (including UBBV2 preamplifier 1MHz-10GHz)

Frequency range: DC- 6 GHz, 4 H-field probes, 1 E-field probe

Impedance: 50 Ohm

Preamplifier: UBBV2 (40dB, DC –8 GHz)

Preamplifier noise figure: 3.5dB (typical)

5) Host: Electromagnetic compatibility test spectrum analyzer (electromagnetic radiation test spectrum analyzer)

Model: SPECTRAN NF-5035

Frequency range: 1Hz to 1MHz (optional expansion to 20 or 30MHz)

Magnetic field measurement range (Tesla): 1pT to 2mT (typical)

Magnetic field measurement range (Gauss): 10nG to 20G (typical) (009 option)

Electric field measurement range: 0.1V/m to 20kV/m (typical)

Resolution Bandwidth (RBW): 0.3Hz to 1MHz (1-3-10 step)

Accuracy: 3% (typical)

5. Application of Anoni's EMC & EMI far-field and near-field testing

During the EMC testing of products, there are often some problems to solve electromagnetic interference. The most important thing is to determine the source of the interference. Only after accurately locating the interference source can we propose symptomatic measures to solve the electromagnetic interference. In the electromagnetic compatibility compliance pre-test, various standard EMC antennas of Germany's Anoni are used for radiation leakage testing, and far-field measurement is generally used. Standard far-field radiation leakage measurement can tell us relatively quantitatively whether the equipment under test complies with national or international EMC standards, whether there is electromagnetic radiation interference that exceeds national or international EMC standards, what is the frequency of the electromagnetic interference, and what is the radiation intensity. For example, the test spectrum is shown in the figure below:

After far-field measurement, it may still be impossible to tell engineers where the serious electromagnetic radiation problem comes from! From the connecting cable? Switching power supply? Communication interface? Or from the PCB circuit board? At this time, we can use the near-field test method of AARONIA spectrum analyzer and near-field probe to locate the exact source of electromagnetic radiation. In order to quickly locate the interference source, AARONIA has launched a near-field probe set with a frequency coverage of DC-9GHz. The probe set includes 4 magnetic field probes and 1 electric field probe, providing the best choice of comprehensive sensitivity and resolution. It can be used for the detection and location of electromagnetic interference sources, helping engineers to quickly and easily analyze various electromagnetic interference (EMI) problems. If the test engineer needs higher sensitivity, AARONIA also provides an external pre-amplifier that can be used with the near-field probe set, providing an almost flat 40dB gain, and the typical value of the noise coefficient is only 3.5dB.

Aaronia's latest SPECTRAN V4 series spectrum analyzer has a typical sensitivity of -170dBm (1Hz). Using high-performance DSP, all test and analysis calculation results are displayed in real time. It can detect the frequency and signal strength of surrounding electromagnetic radiation sources, automatically complete spectrum analysis and complex safety limit calculations, and enrich and improve spectrum software functions, which were only completed by very expensive and complex equipment in the past. Aaronia's SPECTRAN V4 series spectrum analyzer is equipped with EMC antennas, near-field probe sets and external preamplifiers. It has good performance, quick installation, and is easy to use. It has a wide frequency range and good resolution and sensitivity. With the professional MCS spectrum analysis software with rich functions, it provides engineers with the most cost-effective EMI pre-compliance test analysis tool for quickly analyzing and finding EMI interference sources.

6. Typical cases of EMC&EMI electromagnetic compatibility radiation disturbance pre-test

1. Pre-test of electromagnetic compatibility of vehicle navigation system radiated disturbance

Electromagnetic compatibility refers to the ability of a device or system to work properly in its electromagnetic environment and not cause unbearable electromagnetic interference to anything in its environment. For example, while car navigation systems are convenient for the majority of users, people are increasingly concerned about their radiated interference. If the radiated interference seriously exceeds the relevant international or national standards (GB 9254-2008 "Limits and Measurement Methods of Radio Disturbance for Information Technology Equipment" (EN55022)), it will not only affect the normal operation of the in-vehicle system, but may also cause traffic accidents, thereby endangering the lives of people in the car.

The radiation interference of car navigation products includes broadband interference and narrowband interference. The DC/DC converter in the car navigation system works in a pulse state, which will generate strong broadband interference. The speed of the main control chip of the car electronic products is constantly increasing, and the ringing of the rising edge of the clock will generate rich harmonic narrowband interference. To rectify the radiation interference of these car navigation systems, it is necessary to accurately locate their electromagnetic radiation interference in order to prescribe the right medicine. According to the different characteristics of the interference source and the transmission path, the countermeasures such as shielding, filtering, and grounding are applied in a targeted manner to suppress the electromagnetic radiation interference. At this time, the use of the German AARONIA SPECTRAN spectrum analyzer and its near-field probe for near-field diagnosis can accurately find the interference source of electromagnetic radiation in the car navigation system.