近场平面波阐述讲述.pptx

2016年11月9日 Generating a Plane Wave With a Linear Array of Line Sources 1 2 Far field Ampmax/Ampmin 3 4 Fig. 1. Amplitude of the field due to a uniform array (d = 0.5 λ ) of 9 line sources. Fig. 2. Phase of the field due to a uniform array (d = 0.5 λ ) of 9 line sources. 5 6 7 Fig. 3. Optimized amplitude and phase weights of a nine-element array (d =0.5λ ) for an AUT of 10 λ at a distance of 20 λ . 8 Fig. 4. Field phase of an optimized nine-element array (d = 0.5 λ) across an AUT of 10 λ at a distance of 20 λ . Fig. 5. Field amplitude of an optimized nine-element array (d = 0.5 λ) across an AUT of 10 λ at a distance of 20 λ . 9 Fig. 6. The amplitude and phase quality factors of the field radiated by the optimized nine-element array (d = 0.5 λ ) for an AUT of 10 λ at a distance of 20 λ. 10 Fig. 7. Optimized amplitude and phase weights of a nine-element array with nonuniform spacing in the x-direction for an AUT of 10 λ at a distance of 20 λ . Fig. 8. Optimized element spacings in the x-direction of a nine-element array for an AUT of 10 λ at a distance of 20 λ . 11 Fig. 9. Field phase of an optimized (weights and element spacing in x-direction) nine-element array (d = 0.5 λ ) across an AUT of 10 λ at a distance of 20 λ . Fig. 10. Field amplitude of an optimized (weights and element spacing in x-direction) nine-element array (d = 0.5 λ ) across an AUT of 10 λ at a distance of 20 λ . 12 Fig. 11. The amplitude and phase quality factors of the field radiated by the (weights and element spacing in x-direction) optimized nine-element array (d = 0.5 λ ) for an AUT of 10 λ at a distance of 20 λ . 13 14 15 16 17 single source array（dB） K1 K2 K3 L1 0.24 13.6 4.35 3.03 L2 0.06 15.3 4.02 3.71 L3 0.03 17.1 5.62 3.42 single source array K1 K2 K3 L1 360° 60° 29.37° 18.5° L2 360° 42° 36.82° 24.1° L3 360° 60.4° 35.73° 29.58° 18 文献 源阵形式 静区范围 距离 频率 达到水平 文献 源阵形式 静区范围 距离 频率 达到水平 幅度不均度 相位不均度 [2] 圆阵 16 λ *1.6 λ *1.6 λ (121*12*12m) 3 λ (22.5m) 40MHz ? ? [6] 线阵 10 λ 20λ f0 2dB 4