Reserch On Muti-Band Ultra Wideband MMIC Digital Phase Shifter

To address the increasing demand of wide-band phased array radar systems and MIMO (Multiple-input Multiple-output) wireless communication systems, broad-band phase shifters have been developed. With the rapid development of MMIC (Microwave Monolithic Integrated Circuit) technology, wide-band, small-size, light-weight and low-power MMIC digital phase shifters have shown great advantages. So the research on high-performance ultra-wideband MMIC digital phase shifter has important significance and practical value. This dissertation is organized as follow:To make compact ultra-wideband phase shifters, a reflection-type digital phase shifter circuit structure is reserched. This structure is composed of a lumped 3-dB coupler using inductive coupling and a pair of reflective terminating circuits of serial-parallel LC structure. Equations are discussed to generate minimum circuit area and good performance over ultra wide bandwidth. This lumped topology not only has good broadband characteristics, but also reduces chip area and associated die cost.By using 0.15?m pHEMT InGaAs technology, a 4-16 GHz wideband MMIC quadrature phase shifter and an antiphase MMIC phase shifter are proposed and designed. Sonnet and ADS, two kinds of simulation software are used in the design process. The measured results match the EM simulated results, verifing that the compact reflection-type structure can achieve good performance over 4:1 bandwidth. Next, a 3:1 wideband 6-bit MMIC digital phase shifer is proposed and designed. Switch-line type and reflective type circuit topology are used in this 6-bit digital phase shifer. The reasons for the deviation of the measured and simulated results are analyzed and improved direction is put forward. The 6-bit phase shifter has compact structure, small chip size and good phase stability.A 33-37 GHz 6-bit MMIC digital phase shifter is proposed and designed. Embedded switch filter type circuit structure is selected as the phase shifter unit circuit topology. The layout and EM simulated results are given. Compared with other similar MMIC phase shifter designs, the results show that this phase shifter has smaller size, higher phase shift precision and lower insertion loss.A 2.5-8 GHz and an 8-18 GHz ultra-wideband MMIC balun are proposed and designed. The layout and EM simulated results are given. This balun is mainly used to achieve a conversion function from single port to differential port in RF or antenna systems.