Application Of Dispersion Delay Line In Phased Array

Phased-array radar has been widely used in the military, low cost, high performance phase shifter is becoming a hot spot. In this paper, the dispersive delay line which has the advantages of low cost, easy integration and simple manufacturing is used to replace the true-time delay line to applied to the phased-array radar, which can eliminate the aperture effect caused by frequency deviation in the phased-array system. The main contents include:A novel phased-array which uses the dispersive delay line and the frequency converter instead of the delay element (usually phase shifter) is studied. According to the corresponding relationship between the delay time and the frequency of the dispersive delay line, the frequency of the dispersive delay line is controlled by adjusting the frequency of the oscillator, thus changing the delay time difference between the cells in the phased-array. Beam scanning of phased-array antenna is realized finally.Composite Right/Left-handed (CRLH) micro-strip dispersive delay line is researched. On the one hand, the CRLH transmission line can be used to achieve fast phase change, compact structure; on the other hand, it can get a good linear delay characteristic.The key components in the phased-array are designed. The DDS+PLL scheme is adopted to realize the tunable local oscillator, which can easily adjust the local frequency. The SIW band pass filter, the wide band low pass filter, the plane antenna and the Wilkinson power divider in the phased-array system are designed.The construction and testing of the whole phased-array radar system is completed. Test results show that, by adjusting the local frequency, the output phase can achieve a continuous power transfer of 360°, the insertion loss fluctuate within 1.5dB, achieving a range of beam pointing of ±30°, and the aperture effect of phased-array is eliminated.An improved phased-array structure is proposed. In one hand, it can eliminate the distortion of the narrow pulse signal’s waveform in the dispersive delay line; on the other hand, it can eliminate aperture effects of non-point wide bandwidth frequency signals, Further the dispersive delay line applications in the phased-array is broadened.