Research And Design Of Multi-band Ltcc Antenna Switch Module

With the rapid development of mobile communication,3G communication services have gradually come into our lives. As a mobile communication terminal, mobile phone is developing to the trend of multi-frequency, multi-mode, and miniaturization, which will inevitably lead to even more complex communication systems and circuits. It is in contradiction with the requirements for small size and low cost. However the LTCC (Low Temperature Co-fired Ceramic) module, which is used to enhance the integration of radio frequency (RF) communication circuit, becomes one of the keys to solving this problem.In our country, there are many researches about LTCC components, while those of LTCC module still stays at a preliminary stage, it is mainly because of the integration of active and passive components and the high circuit density characteristics of LTCC components, which are the enormous challenges and difficulties of this study.This research is mainly about multi-band SP9T(single-pole nine-throw) antenna switch module(ASM), which is realized by the technology of MMIC (monolithic microwave integrated circuit) and LTCC, and composed of microwave switch and LTCC substrate. At first, two common control devices of microwave circuit are discussed, comparing to each other, PHEMT is selected as control device of the switch, then a series-parallel absorptive MMIC SPDT microwave switch and its layout are designed. Based on the experience and ideas of the SPDT switch, a relatively complex SP9T switch is designed and optimized, so is the layout. Coming to LTCC substrate, the design of low-pass filter embedded in LTCC is discussed and the good three-dimensional simulation results are obtained. Finally based on co-simulation of ADS2008(Advanced Design System 2008) and HFSS(High Frequency Structures Simulator), the integration of the MMIC SP9T switch and two low-pass filters embedded in LTCC is implemented, and the module is optimized in ADS2008, The simulation result shows good VSWR of transmitter and receiver ports, low insertion loss and high isolation, which are better than the required target.The LTCC ASM designed here has a very small size of 4.5mm x 3.2mm×1.4mm, and operates at the frequency of GSM-850/900, GSM-1800/1900 and UMTS800/2100. As far as we know, there is no research report about miniaturized multi-band SP9T ASM, in our country.