Application and Analysis of Three Loop Antenna in Electromagnetic Interference and Compatibility Testing

Introduction
In the design and manufacturing of modern electronic devices, electromagnetic interference (EMI) and electromagnetic compatibility (EMC) testing are crucial to ensuring product performance and safety. The Three Loop Antenna is a specialized antenna used for EMI/EMC testing. Due to its unique design and excellent performance, it is widely used for radiation testing of various electronic devices. This paper will explore the working principle, structural characteristics, and application fields of the Three Loop Antenna, with a particular focus on analyzing the technical specifications and advantages of the LISUN VVLA-30M Three Loop Antenna.

Working Principle and Structure of the Three Loop Antenna
The Three Loop Antenna consists of three mutually perpendicular loop antennas, corresponding to the X, Y, and Z axes. This design allows it to receive and measure the electromagnetic field components in all directions. Each loop antenna converts the detected magnetic field variations into voltage signals through the principle of electromagnetic induction, enabling the detection of electromagnetic radiation.

Compared to traditional single-loop antennas, the Three Loop Antenna has higher sensitivity and directionality, allowing it to capture low-frequency electromagnetic radiation signals more accurately. This makes it particularly effective in high-precision EMI/EMC testing.

Overview of LISUN VVLA-30M Three Loop Antenna
The LISUN VVLA-30M Three Loop Antenna is a standard measuring antenna designed according to CISPR15-2018/GB17743-2007 and EN55015 standards. It is specifically developed for the measurement of radio disturbance characteristics in electrical lighting and similar devices. This antenna can be used in combination with LISUN’s EMI-9KA or EMI-9KB EMI receiver system to measure the magnetic field radiation of the Equipment Under Test (EUT) in the X, Y, and Z planes.

Key Features：
• Frequency Range: 9 kHz to 30 MHz, covering most low-frequency EMI testing needs.
• Loop Diameter: 2 meters, ensuring measurement completion without moving the EUT or antenna.
• Impedance: 50Ω/BNC interface, ensuring stable and consistent signal transmission.
• Sensor Factor: 0 dB for the current probe, providing high-precision measurement capabilities.
• Self-Calibration: The antenna includes a built-in calibration device, pre-calibrated at the factory. Users can also recalibrate it to ensure measurement accuracy.

Technical Specifications

Parameter	Specification
Frequency Range	9 kHz ~ 30 MHz
Loop Diameter	2 meters
Impedance	50Ω/BNC
Sensor Factor	0 dB
Dimensions (L×W×H)	2.4m × 2.4m × 2.5m
Self-Calibration	Supported
Standard Compliance	CISPR15-2018/EN55015, GB17743-2007

These technical specifications demonstrate that the VVLA-30M offers wide frequency coverage, high-precision measurement capability, and strong compatibility, making it suitable for various EMI/EMC testing scenarios.

Application Fields
The Three Loop Antenna, particularly the LISUN VVLA-30M, is widely used in the following areas:

• EMI Testing of Electronic Devices: Used for detecting radiated emissions from consumer electronics, automotive electronics, medical devices, and more to ensure compliance with EMC regulations.
• EMC Certification Testing: Helps manufacturers evaluate whether their products meet international EMC standards, such as CISPR, IEC, and FCC, providing reliable data for product certification.
• Electromagnetic Field Strength Measurement: Assesses electromagnetic field strength in an environment to identify potential sources of interference and ensure proper device operation.
• Immunity Testing: Evaluates a device’s performance under external electromagnetic interference, ensuring stable operation in complex electromagnetic environments.

Advantages Analysis
Compared to other types of antennas, the Three Loop Antenna offers several advantages:

• Omnidirectional Measurement: Three loop antennas cover the X, Y, and Z axes, allowing full electromagnetic radiation measurement without moving the EUT, improving testing efficiency.
• High Sensitivity: The multi-loop design enhances the antenna’s signal reception capability, enabling detection of weak electromagnetic radiation, making it ideal for high-precision testing.
• Robust Structure: The LISUN VVLA-30M features a sturdy structural design, ensuring stable performance across various testing environments.
• Self-Calibration Function: The built-in calibration device ensures measurement accuracy before use, reducing maintenance workload for users.

Conclusion
The Three Loop Antenna plays a critical role in EMI/EMC testing, offering a unique design and excellent performance, making it an ideal choice for electronic device radiation testing. The LISUN VVLA-30M Three Loop Antenna stands out with its wide frequency coverage, high-precision measurement capability, and self-calibration function, providing a reliable and efficient testing solution for users. As the electronics industry continues to evolve, selecting the right Three Loop Antenna will be essential for ensuring EMC compliance and product reliability.

Tags：VVLA-30M