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%.