Noise generated by the high-speed file transferring rate of an SSD device will interfere with WWAN and WLAN sensitivity. Moreover, noise generated by SSD controller also seriously interferes with 2G/3G, LTE, GPS, and Bluetooth. If the noise budget of SSD is not controlled at the R&D stage cautiously, the EMI issues will definitely arise and have a significant impact on computer systems and other interface.

While SSD reads / writes files, noise interferes with WLAN via the USB 3.0 plug / receptacle. The shielding effectiveness of SSD devices has a great impact on the increase or decrease of throughput measurement. The close relationships of USB3.0 receptacle→Plug→dongle→SSD are critically affected by different levels of their shielding effectiveness, noise distribution and the design of SSD controller (See Figure 3). If SSD is poorly designed causing low EMS, Wi-Fi Tethering can cause interference with the read/write functions on the SSD pen drive that is plugged in the computer system.

In order to verify our findings, TRC (Training Research Co. Ltd) have developed instruments such as System Noise Analyzer (SNA), Noise Floor Measurement System (NFS), and Platform Noise Scanner (PNS)…etc. We design and map out testing plans to suit our clients’ specific needs. We have also developed GSM transmitter that simulates a cell phone, which sits by a USB3.0 SSD dongle in use, sending out signal. This is to experiment if Wi-Fi Tethering will still function properly when a cell phone has been placed by the notebook and a USB3.0 SSD dongle in use, which is our human nature to do so.