大角度波束扫描的宽带平面阵研究

本文中介绍了一个可以实现大角度波束扫描的宽带平面声基阵,设计了纵向振动与换能器前盖板弯曲振动相复合的宽带换能器作为基元,保证了基阵具有较好的宽带性能。针对基元的自然指向性难以满足平面阵进行大角度波束扫描的要求,本文中采用通道型橡胶反声障板技术来拓宽阵上换能器的单元指向性,从而实现平面声基阵的大角度、宽带波束扫描。在有限元和边界元进行优化设计的基础上,制作了实验样阵。测试数据表明:在工作频段内换能器响应起伏不超过3 dB,12 kHz时阵上基元指向性达到了140°,基阵-3 dB波束覆盖范围可以达到144.4°,最大旁瓣不超过30%。

Studies on a wide-angle-scanning broadband planar array

In this paper,a wide-angle-scanning broadband planar array is introduced.The broadband transducer is developed to realize the broadband performance of the array.In this transducer,there are two resonance frequencies corresponding to the longitudinal mode caused by the whole transducer and the flexural mode caused by the front mass respectively.Since the natural directivity of the transducer does not meet the requirement of the wide-angle-scanning array,a technology is used to solve this problem.In this technology,a rubber baffle with cylindrical duct is installed to widen the directivity of the transducer.On the basis of the analysis with the FEM and BEM,an experiment array is manufactured and measured.From the experiment results,the fluctuation of the voltage transmit response of the transducer in the operation frequency band does not exceed 3 dB.And the directivity width of the transducer on the array reaches 140° at 12 kHz.The -3 dB beam of the array can scan to 144.4°.And the biggest side lobe does not exceed 30%.