A Component-Level Radio-Frequency Interference Evaluation Method for Mobile Devices

In this letter, a radio-frequency interference (RFI) evaluation method for highly integrated mobile devices, such as smartphones and tablets, is proposed. A near-field specification for noise-emitting components in mobile devices is developed based on near-field emission measurements and RF sensitivity measurements of mobile devices with the bit-error-rate (BER) test. To devise the specification, a derivative relation between the near-field strength of noise sources and the system-level RF sensitivity is newly suggested using the theoretical relationship between the signal to interference and noise ratio and the probability of error in communication systems, and verified with empirical measurements. Using the proposed algorithm, an RFI evaluation specification for commercial camera modules widely used in modern smartphones was established at several RF communication bands.