Murata Manufacturing Co., Ltd., a global leader in electronic components, has demonstrated its expertise by tackling a significant challenge: noise interference in USB 3.2 communication. They wrote a blog post that delves into how Murata addressed this issue, leveraging its advanced technologies and solutions.
USB 3.2, designed for faster data transfer rates, unfortunately this brings with it a challenge—electromagnetic noise. This interference, particularly in the 2.4 GHz band, can severely impact wireless communication devices like Wi-Fi and Bluetooth®, leading to reduced performance and poor user experiences.
Recognizing the growing concern, the USB Implementers Forum (USB-IF) introduced the USB 3.2 RFI System-Level Test (RFI Test) in 2021. This standard aims to ensure that USB devices do not degrade the quality of wireless LAN communications, addressing issues that affect peripheral wireless devices, such as mice and headsets.
Murata’s Approach for Developing Effective Solutions:
Murata, renowned for its expertise in noise suppression and electromagnetic interference (EMI) technologies, stepped up to the challenge with a strategic approach. Here’s how Murata addressed the USB 3.2 noise problem:
Key Products Utilized
- Spectrum Analyzer/Signal Analyzer MS2830A: This versatile tool covers frequencies from 9 kHz to 13.5 GHz and includes built-in functions like a vector/analog signal generator, which aids in efficient development and manufacturing. User-friendly interface, reduced risk of operational errors, and capability to output multiple sets of trace data in CSV format, which improves evaluation efficiency. Click here to learn more about this product.
- Common-Mode Choke Coils (CMCC), NFG Series: These coils are renowned for their excellent noise suppression across various frequency bands including wireless LAN, Bluetooth®, and 5G NR Sub6. It is effective for high-speed transmission interfaces like USB and HDMI, these coils maintain signal integrity while suppressing noise.
Establishment of the RFI Test Environment
Murata’s EMI Division, led by Mr. Masaki Nakase and Mr. Keisuke Oota, established a comprehensive RFI Test environment to comply with USB-IF standards. The setup involved:
- Integration of the Spectrum Analyzer: Utilizing the Anritsu's MS2830A spectrum analyzer, Murata created an environment to measure and evaluate noise generated by USB 3.2 circuits.
- Testing Procedure: A fixture specified by USB-IF was inserted into the Type-C receptacle of the Device Under Test (DUT). This was connected to the spectrum analyzer via coaxial cable to transmit a test signal. Murata’s team assessed whether the noise levels observed met the set limits.
Overcoming Challenges
Murata’s approach involved more than just installing CMCCs. The team conducted rigorous testing and hypothesis verification to tackle the noise issue effectively. Key strategies included:
- Enhancing Grounding: Improving the grounding (GND) of the Type-C connector.
- Strategic Placement of CMCCs: Installing CMCCs at optimal locations to suppress common-mode signals and mitigate noise interference.
Mr. Nakase highlighted the complexity of the problem, stating, “Simply installing our CMCC products was not enough. We needed a deep understanding of the noise mechanisms and a methodical approach to develop effective solutions.”
Results and Industry Impact
Murata’s noise suppression solutions have successfully clarified the noise generation mechanisms and established effective suppression methods. The implementation of impedance matching through reinforced GND and strategic CMCC installation led to significant noise reduction.
The effectiveness of Murata’s solutions has been validated through RFI Tests with laptops as DUTs. Customers have praised the results, noting improved performance in their devices. The collaborative efforts with other manufacturers are ongoing, with Murata’s solutions poised to set new industry standards.
Future Challenges and Opportunities
As technology evolves, new challenges arise. The EMI Division is preparing for advancements such as:
- Emerging Standards: Adapting to new communication standards like Wi-Fi 7, USB 4.0, and PCle 6.0.
- Automotive Innovations: Addressing noise issues in advanced driver-assistance systems (ADAS) and other automotive technologies.
- Miniaturization and High-Density Integration: Handling the increased complexity of self-interference and RF communication quality as devices become more compact and integrated.
Mr. Oota expressed optimism for future developments, stating, “With Anritsu’s advanced testing technology, we aim to create a global framework that enables us to address emerging noise challenges and maintain our competitive edge.”
Murata’s innovative solutions for USB 3.2 noise interference exemplify its commitment to excellence in noise suppression and electronic communication technologies. By leveraging advanced tools like the MS2830A spectrum analyzer and the NFG Series CMCCs, Murata has effectively addressed a critical industry challenge and set a high standard for future solutions.
Murata Manufacturing Co., Ltd., established on December 23, 1950, is a leading provider of electronic devices, including multilayer ceramic capacitors, SAW filters, and EMI suppression filters. The company is headquartered in Nagaokakyo, Kyoto, Japan.
Click here to read this blog post on Murata's Noise Suppression Solution for USB 3.2.
