Development of high linearity duplexers with low passive intermodulation component

We have proposed surface acoustic wave (SAW) duplexer for CDMA/LTE markets. Advancements of the communication system are progressing in accordance with the increase of the data user needs. Technology that uses multi-band and simultaneous communication has been progressing. Effect of mutual interference in the mobile phone increases, deterioration of communication quality is concerned. Therefore, high frequency devices with lower intermodulation distortion (IMD) are required. In this paper, we found that the IMD value can be improved by optimizing the design of High Linearity duplexer using the non-linear SAW simulator which we developed [1]. Several non-linear terms are considered in this Non-linear simulation. Furthermore, in the IMD evaluation system, we used the Low-PIM cables, attenuators, connectors, and new Low-PIM Inductors which we developed for matching. As a result of the trial production of duplexer for BC0/Band13 system, we obtained about 20dB better than the conventional duplexer IMD value. In the future, we will promote optimum design considering to the material properties for further miniaturization and Higher-Linearity.