Wideband Noise Measurement Technique in Duplex Systems for RF Interference

A wideband noise measurement technique with improved isolation is demonstrated for a practical mobile phone. The liquid crystal display (LCD) baseband noise modulated with a transmitted radio frequency (RF) signal interferes with the received RF signal, resulting in an RF desensitization problem. A wideband and simple measurement setup based on a 180° hybrid coupler is proposed and demonstrated to characterize the modulation and its coupling behaviors in duplex systems. This setup overcomes the frequency limitation of a duplexer-based measurement setting. In addition, signal-to-noise ratio improvement in the proposed measurement technique is quantitatively analyzed.

[1]  Chulsoon Hwang,et al.  Noise coupling path analysis for RF interference caused by LCD noise modulation , 2016, 2016 IEEE International Symposium on Electromagnetic Compatibility (EMC).

[3]  Hyun Ho Park,et al.  An Evaluation Method for Radiated Emissions of Components and Modules in Mobile Devices , 2014, IEEE Transactions on Electromagnetic Compatibility.

[4]  Soo-Won Kim,et al.  A method for reducing EMI noise in portable charging applications , 2012, 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG).

[5]  Do-Wan Kim,et al.  The Solutions of LCD Panel (T-Con) EMI Noise for Wireless Integration , 2007, 2007 IEEE International Symposium on Electromagnetic Compatibility.

[6]  Jun Fan,et al.  Investigation of interference in a mobile phone from a DC-to-DC converter , 2013, 2013 IEEE International Symposium on Electromagnetic Compatibility.

[7]  Tzong-Lin Wu,et al.  Compact wideband balanced filter for eliminating radio-frequency interference on differentially-fed antennas , 2015, 2015 IEEE International Symposium on Electromagnetic Compatibility (EMC).

[8]  Jun Fan,et al.  Estimating Radio-Frequency Interference to an Antenna Due to Near-Field Coupling Using Decomposition Method Based on Reciprocity , 2013, IEEE Transactions on Electromagnetic Compatibility.

[9]  Jeong-Taek Kong,et al.  EMI analysis of the LCD panel considering the display driver IC operations , 2005, IEEE 14th Topical Meeting on Electrical Performance of Electronic Packaging, 2005..

[10]  Min-woo Kim,et al.  Chip Level Techniques for EMI Reduction in LCD Panels , 2009, 2009 20th International Zurich Symposium on Electromagnetic Compatibility.

[11]  Hyun Ho Park,et al.  A Component-Level Radio-Frequency Interference Evaluation Method for Mobile Devices , 2013, IEEE Transactions on Electromagnetic Compatibility.

[12]  Chulsoon Hwang,et al.  Radio-Frequency Interference Estimation Using Equivalent Dipole-Moment Models and Decomposition Method Based on Reciprocity , 2016, IEEE Transactions on Electromagnetic Compatibility.

[13]  F. Zhang,et al.  Physics-Based Dipole Moment Source Reconstruction for RFI on a Practical Cellphone , 2017, IEEE Transactions on Electromagnetic Compatibility.

[14]  Markku Rouvala,et al.  Multi-gigabit serial link emissions and mobile terminal antenna interference , 2009, 2009 IEEE Workshop on Signal Propagation on Interconnects.

[15]  Kenji Araki,et al.  LCD baseband noise modulation estimation for radio frequency interference in mobile phones , 2017, 2017 Asia-Pacific International Symposium on Electromagnetic Compatibility (APEMC).

[16]  Seungyoung Ahn,et al.  Experimental investigation of radiated emission from flexible printed circuit (FPC) cable , 2002, 2002 IEEE International Symposium on Electromagnetic Compatibility.

[17]  Etienne Sicard,et al.  Recent Advances in Integrated Circuit Immunity to Radio-Frequency Interference , 2012 .

[18]  Chulsoon Hwang,et al.  Modeling and Estimation of LCD Noise Modulation for Radio Frequency Interference , 2017, IEEE Transactions on Electromagnetic Compatibility.