Ka-band Four-digit Phase Shifter

In this thesis, the research of Ka-band four-bit digital phase shifter is presented.The application of phase shifter is very abroad, for instance , applying to various communication and radar systems,microwave instruments and measurement systems,and especially it has been widely used in phased-array radar.Phase shifter is a key component of phased-array radar. It's performance has direct effects to phased-array radar system. Relative to the classic radar, phased-array radar has little volume, light weight, high accuracy test, quick reaction, low power consumption, broad coverage and other advantage. It becomes the mainstream in the present-day development of radar. Manufacturing a phase shifter of high performance, low cost plays a very important role to the development of phased-array radar.Then there is practice purpose with the research about the topic.It needs high technology and cost for MCM(multi-chip module) and MMIC(Microwave Monolithic Integrated Circuit).So HMIC(Hybride Microwave Integrated Circuit ) has many superior advantages.It is very convenient to produce and debug.While the cost is cut down.Therefore, HMIC technology is used in the design of phase shifter in this paper.The research of this paper is much practical.This dissertation discusses the work principles of several digital phase shifters respectively, and describes their characteristics.Based on this, considering the design requirements which was given and actual technological level,the scheme for Ka-band four-bit digital phase shifter is chosen:22.5 degree and 45 degree used loaded-line phase shifter, 90 degree and 180 degree adopted 3dB branch-line coupler phase shifter;and selected the impedence of microstrip line and circuit structure .Then, the phase shifter is fabricated.Finally, it takes a detailed test to the processed Ka-band four-bit digital phase shifter.The test result is better than expectant guideline: in the 33.9GHz～34.5GHz frequency band,for the 16 phase states, the insertion loss of the phase shifter is lower than 10.71dB,The input/output VSWR(Voltage Standing Wave Ratio) is lower than 2. Moreover, at the mid-frequency of 34.2GHz, the maximum of the phase error is lower than±3 degree. All of performances are better than design requirements.