摘要
常规波束形成中主瓣宽度随频率和方向(方位角和俯仰角)变化,进而影响阵列分辨率及波束形成器的整体性能。为实现频率-方向不变波束形成,提高波束形成可靠性,基于约束优化的思想,提出一种基于二阶锥规划(second order cone programming,SOCP)和傅里叶逆变换(Inverse Fourier Transform,IFT)的宽带频率-方向不变恒定束宽波束形成方法。方法以均匀矩形平面阵为模型,首先采用SOCP波束优化设计方法得到参考波束,再基于IFT设计出参考方向上的频率不变恒定主瓣波束,最后基于提出的SOCP二维方向不变波束形成新方法实现不同频点上的方向不变恒定主瓣波束。经仿真分析,方法设计的波束在数字频率π/2~π、不同方位角及俯仰角指向15°~50°上均具有束宽较恒定的波束,与基于线阵的恒定束宽波束形成方法相比,提高了波束形成器在实际空间中的可靠性,具有一定的相关工程应用参考价值。
Beamwidth varies with frequency and direction （azimuth angle and pitch angle） in conventional beamforming, which has great influence on the resolution of array and overall performance of beamformer. In order to achieve frequency- steering invariant beamforming and improve its reliability, a frequency-steering invariant constant beamforming algorithm based on Second Order Cone Programing （SOCP） and Inverse Fourier Transform （IFT） is proposed, which is based on the optimization of the constraint. Based on planar rectangle array, the expected beam is designed by using the optimization design method of beam based on SOCP first and using IFT to design frequency-invariant constant beamwidth beam in refer- ence direction next. Finally, a new method for 2-D steering-invariant beamforming based on SOCP is proposed to design steering-invariant constant beamwidth beam in reference frequency. Computer simulations show that beam designed by this new method has almost constant beamwidth even with the different numerical frequency varies of pi/2-pi or different azimuths or pitchs varies of 15 to 50 degrees, which improves the reliability of beamformer in actual space compared with the constant beamforming algorithm based on linear array and has a certain reference value on engineering application.
出处
《成都信息工程大学学报》
2017年第2期122-127,共6页
Journal of Chengdu University of Information Technology
基金
国家自然科学基金资助项目(61071159)
