LTCC Front-end Module DCS/PCS Band Design

As global mobile communications get into the third-generation, handsets become necessary in daily life. People make higher demand on the size, performance and cost of the handsets. Low temperature co-fired ceramic(LTCC) technology,which has excellent electrical performance at RF and microwave frequencies, compatibility with semiconductor IC technics , with its main advantage of there-dimensional(3-D) design, has became an important technology of passive integration. The RF part of mobile phone has a lot of passive devices, so FEM becomes of a typical LTCC device. In china, however, LTCC technology trailed the developed countries by at least 5 years, most of the LTCC products are imports. This paper Designed a 2-band and a 3-band FEM using LTCC technology. The FEM designed by us has small size, novel structure, and good performance.Material, manufacture and design are key elements of LTCC technology. This paper focuses on the design, and researches on LTCC front-end module(FEM). It introduces the circuit design and the 3-D structure realization in detail. The circuit design part mainly introduces the duplexer design with lumped apices filter, and the antenna switch design with PIN diode. The 3-D structure realization part introduces the modeling of passive devices and the EM simulation of the whole structure of the module. At the last, it compares a 2-band FEM sample, which is designed by us, with a commercial product of the same type, the measured results of the sample are almost the same as the commercial product, and some parameters of the sample are better than the commercial product .