DBF相控阵天线在超高分辨率机载SAR中的应用

THE APPLICATION OF PHASED ARRAY ANTENNA WITH DBF FOR THE AIRBORNE SAR OF ULTRAHIGH AZIMUTH RESOLUTION

该文从叠加原理和相控阵天线的扫描原理出发,提出了一种灵活方便的波束生成方法。用此方法由微带贴片天线单元组成了145cm×48cm的天线阵,生成了波长为24cm,方位向半功率波束宽度为23°的宽波束。由合成孔径原理可知,条带SAR的方位分辨率随波束宽度的变宽而提高。该文将宽波束天线用于超高方位分辨率机载SAR,计算了天线的性能指标和SAR的系统参数。比较了条带SAR和Spotlight SAR这两种常见的SAR模式的分辨率和测绘范围。

This paper proposes a new flexible method of the beam shaping based on superposition principle and the scanning principle of phased array antenna. We designed a 145cm × 48cm array composed of microstrip patch elements with the wavelength of 24cm. In the azimuth direction, the pattern of this array has 23?half-power beam width. According to the principle of the synthetic aperture, the azimuth spatial resolution of the strip SAR is improved dramatically with wide beam. In this paper, the wide beam antenna array is used as the antenna of an airborne SAR with ultrahigh azimuth resolution. The parameters of the antenna and the SAR system are calculated and are compared between the strip-mapping SAR and the Spotlight SAR.