Here is the comprehensive technical article on the LISUN RFCI61000-6 series, structured according to your specifications.

Abstract

The RFCI61000-6 RF Conducted Immunity Test System is a critical instrument for EMC compliance validation, designed to test equipment susceptibility to conducted RF disturbances from 150 kHz to 230 MHz. This system integrates a signal source, power amplifier, and power meter into a single chassis, offering a streamlined solution for manufacturers and test labs. With dual power variants (35W and 85W) and support for multiple injection methods, it ensures rigorous adherence to international standards. This article provides a technical deep-dive into the system’s architecture, performance metrics, and its indispensable role in achieving EMC compliance for industries ranging from medical devices to industrial controls, focusing on practical engineering application.

1.1 Integrated Signal Source and Power Amplifier Module

The LISUN RFCI61000-6 series departs from modular, bench-top assemblies by integrating the RF signal generator and broadband power amplifier within a single enclosure. This design minimizes internal cabling losses and reduces the overall footprint of the test setup. The signal source generates continuous waves (CW) with amplitude and pulse modulation capabilities, directly feeding into the amplifier stage without external patch cables. This integration lowers the voltage standing wave ratio (VSWR) within the signal chain, which is critical for maintaining calibrated power levels across the frequency sweep.

1.2 Built-in Power Meter and Calibration Loop

An integrated power meter provides real-time feedback of the forward and reflected power delivered to the equipment under test (EUT). This closed-loop system allows for automated leveling, ensuring that the disturbance level at the EUT port remains constant despite variations in impedance. The power meter is calibrated to measure peak envelope power and average power, which is essential for setting the 80% amplitude modulation (AM) depth required by IEC 61000-4-6. This configuration eliminates the need for an external RF millivoltmeter and simplifies the pre-calibration process defined in Clause 7.1 of the standard.

1.3 Touchscreen Interface and Automation Capabilities

The system features a high-resolution touchscreen interface that replaces traditional knob-and-button controls. This interface provides a single point of control for setting frequencies, modulation types, and output levels. For automated test sequences, the RFCI61000-6 supports remote control via Ethernet and GPIB interfaces. This connectivity allows the system to be integrated into a larger EMC test automation suite, enabling sequential testing across multiple frequency points and modulation indices without manual intervention, significantly reducing test duration for product compliance validation.

2.1 Current Clamp (Injection Clamp) Application

The primary injection method for conducted immunity testing is the current clamp, which allows RF disturbance to be coupled onto signal, data, and power cables without direct electrical contact. The RFCI61000-6 series is designed to drive standard injection clamps (such as the LISUN CDN series) with sufficient power to reach the 10V or 20V test levels. This method is preferred for multi-conductor cables where a direct connection via a CDN is impractical. The system delivers a stable output up to the required 230 MHz frequency, ensuring the clamp’s transimpedance remains effective across the entire test bandwidth.

2.2 Direct Coupling via CDN (Coupling-Decoupling Network)

For single-phase and three-phase power lines, direct coupling using CDNs provides the most repeatable results. The RFCI61000-6 system supports a range of LISUN CDNs designed for currents from 16A to 100A. The 35W variant is typically sufficient for most CDN applications up to 3V test levels, while the 85W variant ensures headroom for higher test levels (10V open-circuit) on capacitive EUTs. The system automatically detects the connected CDN (if using LISUN’s smart CDN series) and adjusts its calibration limits to account for the specific insertion loss of the network.

2.3 EM-Clamp and Bulk Current Injection (BCI)

Beyond standard CDNs, the system is compatible with EM-clamps (electromagnetic clamps) for coupling disturbances onto unscreened cables and Bulk Current Injection (BCI) probes for larger cable bundles. The 85W model is particularly suited for BCI methods, where high loop impedance can require significant power to maintain the required current limit. The system’s low harmonic distortion output ensures that the injected disturbance is a pure sinusoidal wave modulated by the selected envelope, preventing false failures caused by harmonic content rather than the fundamental test frequency.

3.1 Dual Power Variants: 35W vs. 85W

Selecting the correct power variant is critical for matching the test standard’s severity level with the EUT’s impedance characteristics. The 85W model provides a significant advantage when testing high-power inverters or charging stations where the input impedance is low, requiring higher voltage swing to achieve the specified disturbance level.

3.2 Frequency Stability and Leveling Accuracy

Maintaining a stable output level across the 150 kHz to 230 MHz band is a key performance indicator. The RFCI61000-6 utilizes a frequency-synthesized generator with a stability of < 5 ppm. The automatic level control (ALC) circuit, driven by the internal power meter, maintains the output level within ± 0.5 dB of the set value after calibration. This accuracy is essential for meeting the performance criterion defined in IEC 61000-4-6, Clause 7.2, which requires the disturbance level to be maintained within a +0 dB to -1.5 dB tolerance during the test.

3.3 Modulation Capabilities: AM and Pulse

The system provides two essential modulation modes: 1 kHz amplitude modulation with 80% depth (sine wave envelope) and pulse modulation (typically 1 Hz or 5 Hz). The 80% AM mode is the standard requirement for most conducted immunity tests, simulating real-world interference. The pulse modulation capability is used for simulating switching transients and digital communication interference. The modulation source is internal, but an external modulation input is also available for complex signal scenarios required by specific product family standards.

4.1 Adherence to IEC 61000-4-6 and EN 61000-4-6

The system is designed to fully meet the test requirements of IEC 61000-4-6 and its European equivalent, EN 61000-4-6. It supports all four injection methods: CDN, current clamp, EM-clamp, and BCI. The test levels (1V, 3V, 10V RMS) and frequency ranges (150 kHz – 80/230 MHz) are pre-programmed within the system’s firmware. The system’s ability to perform the pre-calibration and verification steps (as per IEC 61000-4-6 Clause 6.1 and Annex A) using the internal power meter streamlines the setup process.

4.2 Chinese National Standard Compliance (GB/T 17626.6)

For manufacturers targeting the Chinese market, the system complies with GB/T 17626.6, which is essentially a harmonized equivalent of IEC 61000-4-6 with minor localization modifications regarding test level tolerance and injection clamp calibration. The RFCI61000-6 series is manufactured by LISUN, a company widely recognized in the Chinese EMC market. The system includes specific pre-sets for GB/T standards, ensuring that test parameters like the step size (1% of frequency) and dwell time meet local regulatory requirements.

4.3 CISPR and Automotive Standard Pre-Compliance

While primarily designed for generic immunity standards, the system’s wide frequency range up to 230 MHz allows for pre-compliance testing against automotive standards (such as ISO 11452-1) and military standards (MIL-STD-461 CS114) when using appropriate injection probes. The 85W variant provides the necessary drive capability for high-power BCI probes. This versatility allows a single system to be used for pre-scanning devices destined for multiple regulatory environments before sending them to accredited labs for full compliance testing.

5.1 LED Lighting and Power Equipment

LED drivers and power supplies are susceptible to conducted RF interference on their AC input lines. The RFCI61000-6 system, paired with a 16A CDN, is used to inject disturbances onto the mains input of LED luminaires and switching power supplies. Testing ensures that the internal PWM controllers do not deviate from their set frequency, preventing flicker (in lighting) or output ripple (in power supplies). The 35W model is generally sufficient for these applications, as the impedance of the driver’s input stage is typically high enough to require moderate power.

5.2 Medical Devices and Industrial Controls

Medical devices must meet strict immunity requirements to ensure patient safety. The system is used to test sensors, patient monitoring equipment, and motor controls used in operating theaters. The 80% AM modulation simulates interference from radio transmitters (e.g., walkie-talkies) which are common in industrial environments. For industrial controls with long cable runs, the 85W model is preferred to ensure the disturbance level is maintained along the entire cable length, especially when using BCI probes on large cable bundles.

5.3 New Energy Charging Stations and Communications Equipment

Electric Vehicle (EV) charging stations represent a challenging test environment due to their high-voltage circuitry and communication lines (PLC). The RFCI61000-6 is used to verify the immunity of the control pilot signal and the power line communication (PLC) interface. The 85W model is essential here because the low impedance of the charging pile’s power electronics requires significant current drive to achieve the required voltage level. For communications equipment, the system tests Ethernet ports via a CDN-M2/M3 coupling network, ensuring data transmission remains error-free during RF injection.

6.1 Pre-Calibration and Setup

The test procedure begins with pre-calibration, where the system is set to the required test level (e.g., 10V) into a 150-ohm load (for CDN testing). The internal power meter records the forward power required to achieve this level. This data is stored as a calibration table for the frequency sweep. The user then connects the EUT and the appropriate injection device. The system’s interface allows the operator to select the standard (IEC/EN), test level, and frequency step size (1% or 0.01% of the fundamental frequency).

6.2 Automated Frequency Sweep and Monitoring

Once initiated, the system automatically sweeps from 150 kHz to 230 MHz. At each frequency step, the system dwells for the required time (typically 1-3 seconds) before moving to the next point. During the dwell, the operator (or a monitoring camera) observes the EUT for performance degradation. The system logs the forward power, reflected power, and frequency for each point. If the reflected power exceeds a set threshold (indicating a high VSWR or EUT damage), the system can be configured to shut down automatically to protect the amplifier.

6.3 Data Logging and Report Generation

Post-test analysis is facilitated by the system’s data logging capabilities. The RFCI61000-6 generates a comprehensive test report including the frequency list, applied disturbance levels, and modulation settings. This data can be exported via USB or Ethernet for integration into a final compliance report. The ability to log the actual power delivered to the EUT (accounting for insertion loss of cables and CDNs) provides traceability and supports ISO 17025 quality management requirements for testing laboratories.

7.1 Insertion Loss Compensation (AMN/CDN)

Proper calibration requires accounting for the insertion loss of the interconnecting cables and the CDN. The RFCI61000-6 includes a calibration wizard that guides the user through measuring these losses. The system stores the loss profile across the frequency range and automatically compensates the output power during the test. This ensures that the disturbance level at the EUT port meets the specified voltage, rather than just measuring it at the amplifier output, a requirement highlighted in IEC 61000-4-6, Clause 7.3.

7.2 Verification with External Monitoring Equipment

For accredited labs, the system allows for an external verification step. While the internal power meter is calibrated, a second external RF voltmeter or power sensor can be used to measure the voltage at a CDN’s EUT port (using a 150 ohm to 50 ohm adapter). The system’s manual control mode allows the user to adjust the output at specific frequencies to match the external meter’s reading. This dual-path verification is a common practice during laboratory audits and ensures that the system’s own metrology is within tolerance.

The LISUN RFCI61000-6 series offers a technically robust and practical approach to conducted immunity testing. By integrating the signal source, amplifier, and power meter into a single unit, it reduces the complexity and footprint of the test setup while improving measurement accuracy through reduced internal VSWR. The choice between the 35W and 85W variants allows laboratories to match the system’s power output to the specific impedance challenges of their EUT, from low-power LED drivers to high-power EV charging stations. Full compliance with IEC 61000-4-6, EN 61000-4-6, and GB/T 17626.6 ensures global regulatory acceptance. For engineering teams tasked with EMC compliance, this system provides a reliable, automated path to validating product robustness against conducted RF disturbances.

Q1: How does the LISUN RFCI61000-6 handle the 80% amplitude modulation depth required by IEC 61000-4-6?
A: The system automatically generates the 1 kHz sine wave modulation envelope with a depth of 80% (modulation index m=0.8) when the “AM” mode is selected. The internal signal chain ensures that the carrier wave (from 150 kHz to 230 MHz) is modulated by the 1 kHz signal, resulting in a peak voltage that is 1.8 times the RMS voltage of the unmodulated carrier. The closed-loop power meter measures the average power and calculates the peak envelope power (PEP) to verify the modulation depth is correct. This is critical because the IEC standard requires testing at 80% AM to simulate real-world interference from radio communication signals.

Q2: When should a lab choose the 85W model over the 35W model for the RFCI61000-6?
A: The decision is driven by the impedance of the Equipment Under Test (EUT) and the required test level. The 35W model is suitable for standard single-phase power supplies, LED drivers, and control boards where the input impedance is reasonably high (greater than 50 ohms). The 85W model is necessary when testing low-impedance devices, such as high-power industrial inverters, EV charging piles (with input impedances below 10 ohms), or when using Bulk Current Injection (BCI) probes on large cable bundles. Higher voltage test levels (10V or 20V) on these low-impedance loads require more power, and the 85W model ensures the system can maintain the required disturbance level without clipping or distortion.

Q3: What is the process for calibrating the system with a specific LISUN CDN?
A: Calibration involves a two-step process. First, you perform a “pre-calibration” of the system’s output, where the amplifier output is connected to a dummy load or the CDN’s RF input port. The system measures the forward power required to achieve the target voltage (e.g., 3V) at the CDN’s EUT port, accounting for the CDN’s specified insertion loss. Second, the system stores this profile in memory. During the actual test, the system’s internal power meter adjusts the amplifier gain in real-time based on this calibration profile to ensure the voltage at the EUT port remains stable, even if the impedance of the EUT varies. This method fulfills the requirements of IEC 61000-4-6 Clause 6.2 regarding pre-calibration of the test setup.