Miniaturized power dividers with integrated bandpass response based on BAW coupled resonator filters

Abstract

With the spectrum more and more overcrowded, filters and duplexers are drivers of the technology in the discrete device mobile market. The user segment of wireless communication systems leverages the outstanding performance of filtering devices based on acoustic wave resonators. But so far, these technologies have not covered the rest of the RF passive elements in a Front End Module. The use of Bulk Acoustic Wave technology overcomes the miniaturization issue. The acoustic technology exhibits key properties which allow a significant size reduction. In an RF-Front End Module, the passive devices are under continuous pressure to shrink. Some conventional power dividers are not adequate for the high level of miniaturization demanded. To contribute on the size reduction demands of dividers, we have studied two different topological designs which applies bulk acoustic wave technology. Specifically the two proposed devices are based on Coupled Resonators Filter structures. Guidelines for the design of both 3-dB power dividers are described on this paper. We illustrate the designs with two splitters based on the two topologies for application on W-CDMA and their simulated performances. Both dividers have embedded passband filtering responses and have all the ports matched. Furthermore, the designed splitters simplify the fabrication of CRF because almost all the multilayer films are uniform.