Performance improvement of Fresnel beamforming using dual apodization with cross-correlation.
Performance improvement of Fresnel beamforming using dual apodization with cross-correlation.
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DOI：
10.1109/tuffc.2013.2589
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发表时间：
2013-03
期刊：
影响因子：
--
通讯作者：
Yen JT
中科院分区：
文献类型：
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作者：
Nguyen MM;Yen JT
菲涅耳波束形成是一种波束形成方法，其具有与物理菲涅耳透镜形状相似的延迟轮廓。通过4到8个发射通道，2个接收通道和一个单极/单投开关网络，菲涅耳波束形成可以减小波束形成器的尺寸，成本和复杂性。菲涅耳波束形成的性能高度依赖于相位环绕和时延量化引起的焦误差。之前，我们证明了菲涅耳波束形成相对于延迟和和（DAS）波束形成的性能与f数= 2和50%带宽下的线性阵列相当。然而，菲涅耳波束形成的焦误差更大，因为元件之间的路径长度差异更大，如曲线阵列与线性阵列的情况。在本文中，我们提出了菲涅耳波束形成的概念和性能评估，并结合了一种新的曲线阵列杂波抑制方法，称为互相关对偶apodiization （DAX）。菲涅耳波束形成后DAX的噪比在f数= 3时最高。在f数= 3时，实验结果表明，使用DAX，菲涅耳波束形成的比噪比从3.7提高到10.6，而DAS波束形成的比噪比为5.2。空间分辨率不受DAX的影响。在f数= 3时，DAX波束形成的菲涅耳波束横向宽度和轴向脉冲长度分别比DAS波束形成的波束宽度和轴向脉冲长度大1.44和1.00 mm（分别大14%和21%）。实验结果与仿真结果吻合较好。
Fresnel beamforming is a beamforming method that has a delay profile with a shape similar to a physical Fresnel lens. With 4 to 8 transmit channels, 2 receive channels, and a network of single-pole/single-throw switches, Fresnel beamforming can reduce the size, cost, and complexity of a beam-former. The performance of Fresnel beamforming is highly dependent on focal errors resulting from phase wraparound and quantization of its delay profile. Previously, we demonstrated that the performance of Fresnel beamforming relative to delay-and-sum (DAS) beamforming is comparable for linear arrays at f-number = 2 and 50% bandwidth. However, focal errors for Fresnel beamforming are larger because of larger path length differences between elements, as in the case of curvilinear arrays compared with linear arrays. In this paper, we present the concept and performance evaluation of Fresnel beamforming combined with a novel clutter suppression method called dual apodization with cross-correlation (DAX) for curvilinear arrays. The contrast-to-noise ratios (CNRs) of Fresnel beamforming followed by DAX are highest at f-number = 3. At f-number = 3, the experimental results show that using DAX, the CNR for Fresnel beamforming improves from 3.7 to 10.6, compared with a CNR of 5.2 for DAS beamforming. Spatial resolution is shown to be unaffected by DAX. At f-number = 3, the lateral beamwidth and axial pulse length for Fresnel beamforming with DAX are 1.44 and 1.00 mm larger than those for DAS beamforming (about 14% and 21% larger), respectively. These experimental results are in good agreement with simulation results.