X-band Six Digital Phase Shifter

Phase shifter is wildly used in the area of communication and radar systems, especially in the Phased Array radar systems. It controls the phase of every radiation unit of the aerial aperture through the way of the electricity, in order to realize the beam scanning, which is the key component of Phased Array radar.This thesis researches basic principle of microwave digital phase shifter deeply, reviews different theories of all kinds of microwave digital phase shifter circuit. Considering the defect of switched-line phase shifter, a type of switched-line with loaded-line is used in this thesis. By this method, improved wide band X-band 6-bit digital phase shifter is presented in the paper. The proposed phase shifter is fabricated using a switch-type circuit loaded line for 180°, 90°, 45°, 11.25°and 5.625°, using 3dB branch-line coupler phase shifter and the switched-line phase shifter for 22.5°degree to contrast. The result indicates: the phase shifter used the 3dB branch coupler insertion loss reduces 0.8dB. In defect of phase shifter model in ADS software DesignGuid, a model is added in it.This article completes the X-band phase shifter development finally. Its overall appearance is 68mm×48mm×10mm, reduces above 30% compared to the domestic similar products'volume. The trial result shows that the phase shifter accuracy is±6°over the whole band of 9.3 GHz-10.7 GHz with the VSWR less than 1.8, and the insertion loss is lower than 9dB. All of performances are better than design requirements.