6. Ultra Wideband Mmic Digital Phase Shifter And Design

RF monolithic microwave integrated circuit (MMIC) technology providing a key component of the core components and devices for modern wireless communications system, location system, sensing system, and identification system so on, and played a key role part for the development in today's wireless technology.Phase Shifter is used as send / receive (T/R) in phased array radar, through which control the radiation unit and then control the array of phase-change to achieve rapid scanning beam in the air, because it has an extremely important military use background and has been paid much more attention . With years of development and new technologies, based on GaAs technology, with the MMIC design methods, the technology of phase shifter developed rapidly. As developed countries have the most advanced MMIC technology and military embargo on our country, and a series of reasons for the processing technology in our own conditions on the backward, so that we have a sense of urgency for modernization of our nation's military technology, it take an important and practical significance in the MMIC phase shifter research and the entire process of MMIC.First, this paper analyzed many circuits and the basic principles of digital phase shifter, and then analyzed various passive components in the composition of phase shifter, focusing on the core control device equivalent PHEMT used in phase shifter , then design equivalent circuit model to fit with the S parameters of PHEMT, discuss and compare the different median phase shifter topology ,at last choose suitable circuit topology, then use software of Agilent's ADS, simulate and optimize of the design 6～18 GHz ultra wideband MMIC six bits phase shifter, achieved excellent electrical properties.The six bits MMIC digital phase shifter using 0.5μm InGaAs PHEMT process to achieve, after six bits ware connected, on 6～18 GHz working band, the indicators of 64 kinds of situations is: the various phase shift state for the worst error is±3°, typical VSWR value of input is 1.5, typical VSWR value of output is 1.8, the maximum and min insertion loss for the cascade is 8.22 dB and 4.8dB, the total chip area is 4mm×3.5mm×0.1mm , this design results are better than the design requirements and have enough cushion for production.