Conducted Interference Test: A Comprehensive Overview of EMI Test Systems with LISUN EMI-9KB EMI Test Receiver

Abstract
Conducted interference testing is a critical process in evaluating the electromagnetic compatibility (EMC) of electronic devices and systems. This paper provides a comprehensive analysis of conducted interference testing, focusing on the role of the LISUN EMI-9KB EMI Test Receiver in conducting EMI conducted interference tests. We explore the principles, setup, and applications of conducted interference testing, with an emphasis on the importance of accurate measurements for regulatory compliance. The paper also presents practical data, system configurations, and theoretical insights on the conducted interference test process.

1. Introduction
Electromagnetic interference (EMI) is a significant concern in modern electronics, particularly as devices become more compact and integrated. Conducted interference refers to the unwanted electromagnetic energy that is transferred along conductive paths, such as power lines, signal cables, or grounding systems. This form of interference can disrupt the performance of nearby electronic devices or systems and must be carefully controlled to meet regulatory standards.

Conducted interference tests are designed to measure and evaluate the amount of electromagnetic noise that is coupled onto a conductor. The tests are crucial for ensuring that electronic devices comply with electromagnetic compatibility (EMC) standards, such as those defined by the International Electrotechnical Commission (IEC), European Union (EU), and the Federal Communications Commission (FCC).

One of the essential tools for conducting EMI tests is the EMI test receiver. The LISUN EMI-9KB EMI Test Receiver is specifically designed to assess conducted and radiated interference from electrical and electronic equipment. This paper delves into the technical specifications, operation, and use of the LISUN EMI-9KB to carry out conducted interference tests.

2. Conducted Interference Test Principles

2.1 Electromagnetic Interference (EMI) Overview

Electromagnetic interference (EMI) arises from unwanted electromagnetic energy emitted by electrical devices or systems, which can disrupt the operation of other devices. EMI is typically classified into two categories:

Radiated Interference: EMI that propagates through the air.
Conducted Interference: EMI that is transmitted along cables, wires, or other conductors.
In the context of conducted interference, the disturbance is coupled into the power line or signal line, propagating through the device under test (DUT) and potentially interfering with other equipment.

2.2 Conducted Interference Test Setup

Conducted interference testing typically involves injecting a signal into the system under test to simulate electromagnetic disturbance and measuring the levels of EMI that are conducted along the cables connected to the DUT. The setup involves several key components:

DUT (Device Under Test): The electronic device being tested.
Coupling Network: Used to inject the interference signal into the device.
EMI Test Receiver: Used to measure the conducted emissions.
Measurement Equipment: Includes oscilloscopes, spectrum analyzers, and other diagnostic tools.
Test Environment: A controlled chamber or lab environment designed to minimize external noise and interference.

2.3 Conducted Interference Measurement

The measurement of conducted interference involves detecting the unwanted electromagnetic signals coupled into the conductors of the DUT. Typically, a current probe or LISN (Line Impedance Stabilization Network) is used to capture the current that flows through the device’s power or signal lines. This signal is then fed to the EMI test receiver, which provides data on the intensity and frequency of the interference.

The test procedure follows standardized test protocols, such as those established by the CISPR 16, IEC 61000-4-6, or EN 55011, which outline specific frequency ranges, test conditions, and measurement equipment specifications.

3. The LISUN EMI-9KB EMI Test Receiver

The LISUN EMI-9KB EMI Test Receiver is a specialized instrument used for EMI conducted and radiated interference testing. This receiver is designed to measure both conducted and radiated electromagnetic interference, offering comprehensive EMC compliance testing for a wide range of devices. Below, we explore its features and functionality in more detail.

3.1 Technical Specifications

The LISUN EMI-9KB EMI Test Receiver is equipped with advanced features that make it ideal for conducting interference tests. Its primary specifications include:

Specification	Details
Frequency Range	9 kHz to 30 MHz
Measurement Bandwidth	10 kHz, 120 kHz, 1 MHz
Dynamic Range	80 dB
Max Input Voltage	30 Vrms
Detection Mode	Peak, Average, Quasi-Peak
Impedance	50 Ω
Built-in LISN (Line Impedance Stabilization Network)	Yes
Test Signal Input	BNC, N-type
Display	8-inch TFT LCD
External Connections	USB, Ethernet, GPIB (optional)
Compliance Standards	CISPR 16, IEC 61000-4-6, EN 55011

The LISUN EMI-9KB is designed for accuracy, allowing for precise measurements across a wide frequency range, and its high dynamic range ensures that both weak and strong signals can be captured effectively.

3.2 Operation

The EMI-9KB operates by measuring the conducted interference through either a line impedance stabilization network (LISN) or a current probe. The device can be connected to the DUT, and the emitted signals are captured through the LISN or other coupling networks. The test receiver then processes these signals and presents the data in a format suitable for analysis.

The receiver allows for measurements in different detection modes, including peak, average, and quasi-peak, and can also integrate the data over time for more comprehensive testing. This flexibility ensures that the LISUN EMI-9KB is capable of meeting a variety of testing standards and requirements.

3.3 Applications

The LISUN EMI-9KB is widely used in the following applications:

Consumer Electronics: Ensuring that electronic devices such as televisions, computers, and smartphones meet EMC standards.
Industrial Equipment: Testing machinery and control systems to ensure they do not emit harmful conducted interference that could disrupt other systems.
Automotive Electronics: Ensuring that automotive electronic components do not interfere with vehicle systems or external devices.
Telecommunications: Verifying that communication equipment complies with interference standards to avoid signal degradation.

4. Conducted Interference Test Procedure with LISUN EMI-9KB

4.1 Preparation

• Set up the test environment: Ensure that the test environment is free from external electromagnetic interference and that the LISUN EMI-9KB is calibrated.
• Connect the DUT: Attach the device under test to the coupling network and ensure all connections are secure.
• Configure the LISUN EMI-9KB: Set the appropriate frequency range, detection mode, and measurement bandwidth according to the standards required for the test.

4.2 Testing

• Perform the test: Initiate the conducted interference test and allow the LISUN EMI-9KB to capture the emitted signals.
• Monitor the results: The EMI test receiver will display the measurements on its screen, and the data can be recorded for further analysis.
• Compare with standards: The measured interference levels should be compared with the relevant EMC standards, such as CISPR 16, to ensure compliance.

4.3 Data Analysis

Once the test is complete, the data is analyzed for compliance with the relevant standards. If the interference levels exceed the allowed limits, corrective measures may be necessary, such as adding filters or improving shielding on the DUT.

5. Conclusion
Conducted interference testing plays a critical role in ensuring the electromagnetic compatibility of electronic devices. The LISUN EMI-9KB EMI Test Receiver provides a comprehensive solution for conducting such tests, offering precise measurements and compliance with international EMC standards. By using the LISUN EMI-9KB, manufacturers can ensure that their products meet the necessary regulatory requirements, minimizing the risk of interference and improving product reliability.

The detailed understanding of the conducted interference test process, coupled with the advanced capabilities of the LISUN EMI-9KB, makes it an essential tool for any EMC testing laboratory or manufacturer seeking to ensure the quality and compliance of their electronic products.

Tags：EMI-9KB