The mechanism of a universal serial bus 3.0 connector caused radio frequency interference (RFI) to a nearby antenna is studied. The connector radiation is modeled by an equivalent stripline-fed slot antenna, based on the analysis of the common mode current path on the connector structure. With the proposed connector model, the original connector radiation source can be replaced by an equivalent magnetic dipole source, which is directly correlated with the physical quantity on the connector. Applying reciprocity theorem, the equivalent dipole source can be applied to predict the coupled noise power to the antenna. The proposed connector radiation mechanism and model are validated through full-wave simulation and measurement. The application of the magnetic dipole source for RFI estimation is demonstrated in a real laptop system.

Mechanism and Validation of USB 3.0 Connector Caused Radio Frequency Interference

In the SoC (System on Chip) environment, one I/O will have power supply noise coupling from other I/Os due to the proximity of different I/O’s noise source and lack of mitigation mechanisms at the victim. It becomes more important if the victim I/O is very sensitive to certain noise spectrum. This paper describes a methodical approach for characterizing the Power delivery network coupling from one I/O to the other I/O & also provides solution to reduce this coupling noise which is validated across different Silicon. Early identification of such coupling mechanisms is very important, as the necessary mechanisms to mitigate the coupling can be implemented in the SoC development phase.

Power Supply Noise Coupling Mitigation across High Speed Serial Links

In this paper, system-level coexistence impact of USB type-C connector with WiFi radio is assessed in comparison to USB type-A. As data rate increases and small form factor is highly demanded, adoption rate of USB Type-C connector has been substantially increasing. As compared to USB-A connector, USB-C connector has not been extensively investigated for RFI risk and coexistence impact of USB-C and WiFi radio. Therefore, radiated RFI noise and WiFi throughput of USB-C connector is characterized and compared to USB-A connector. The USB-C RFI risk assessment shows that 20dB RFI reduction realizes 180% throughput improvement as compared to one of the USB-A connector. The results demonstrate that RFI-shielded USB type-C connector has much less impact on wireless communication than USB-A, resulting in wireless performance improvement in mobile computer platforms.

System-level coexistence impact of USB type-C and type-A connectors with WiFi radio

An efficient and effective methodology for platform power delivery and power integrity (PD-PI) co-analysis and design optimization has been developed, for investigating high yield loss, to support SoC validation. Both frequency and time domain results have demonstrated good correlation between simulation and lab measurement. Consequently it enabled quick verifying the root cause and optimizing work-around power delivery fixing solutions, and further provided optimal PD configuration scheme to key customers for their platform design.

Platform PI-PD co-design and validation for power efficient HSIO interfaces

Scalable platform power integrity design approach is first time developed, together with standard PI model (SPIM) and unified PI target (UPIT) to efficiently address HVM customers' largely design differentiation with power delivery network design & optimization, and then design review & sign-off, to flexibly make trade-off between cost and performance, or between stack-ups and PD BOM cost. Such standardized design architecture has been adopted & deployed by leading EDA tools.

Xingjian Kinger Cai

Papers

System-level coexistence impact of USB type-C and type-A connectors with WiFi radio

Platform PI-PD co-design and validation for power efficient HSIO interfaces

Scalable platform power integrity design approach with standard PI model (SPIM) and unified PI target (UPIT)