Research And Design Of A New Type Of The Gsm / Dcs Dual-band Ltcc Antenna Switch Module

The development trend of mobile terminals, such as cell phone, was miniaturization, multi-band, muti-function, multi-mode and low manufacturing cost, and there was more and more great demand for less R&D time and R&D fee. LTCC module technique was considered as the best solution to the integration of RP communication circuits, and became a hot issue of research. Under this kind of condition, the GSM/DCS dual band LTCC antenna switch module (ASM) was studied and developed in this paper, to break the monopoly of the American, European and Japanese enterprises.First of all, the method to establish the model of microwave solid control device was introduced, the comparison between different microwave switch circuits was studied and the final layout was made. The developed PHEMT SPDT microwave monolithic switch had a good performance of magnitude and phase characteristic in ultra wide band, which was designed with the control device model, the switch topology and the circuit optimization techniques in this paper. The PIN SPDT microwave switch developed in this paper took the advantage at the easy bias circuits, which had the coding function.Then, the method to design LTCC LPF/HPF/BPF filters and diplexers was covered. A few solutions were developed, and the method how to get the LTCC 3D circuits with traditional network synthesization method (NSM) was introduced. A Bluetooth^TM LTCC band pass filter was designed and implemented and the experimental data agree very well with the 3-D simulation. As we known, this filter was the smallest one of what were designed with such low dielectric capacitance in Bluetooth^TM band.In the end, a solution to GSM/DCS dual band LTCC antenna switch module was developed with the integration of SPDT microwave switches and LTCC filters and diplexers, and the characteristics were good enough to implement.