摘要
Refraction index mismatch between fiat left-handed metamaterial （LHM） lens and its surrounding medium generally destroys the focusing of flat LHM lens and degrades the performance of near-field target detection by using fiat LHM lens. For LHM lens of refraction index mismatch within ±30%, numerical simulations demonstrate that lenses with large refraction index may suffer less resolution degradation than lenses with small refraction index, and the enhancement of refocused microwave backscattered from target can be subsided by up to approximately 5.5 dB. The refraction index mismatch will also shift the target position in the reconstructed image so that theoretical prediction of target position needs to be modified.
Refraction index mismatch between fiat left-handed metamaterial （LHM） lens and its surrounding medium generally destroys the focusing of flat LHM lens and degrades the performance of near-field target detection by using fiat LHM lens. For LHM lens of refraction index mismatch within ±30%, numerical simulations demonstrate that lenses with large refraction index may suffer less resolution degradation than lenses with small refraction index, and the enhancement of refocused microwave backscattered from target can be subsided by up to approximately 5.5 dB. The refraction index mismatch will also shift the target position in the reconstructed image so that theoretical prediction of target position needs to be modified.
基金
Supported by the National Natural Science Foundation of China under Grant 60771041, Department of Personnel of Jiangsu Province under Grant 06-E-060, and Department of Education of Jiangsu Province under Grant 05KJB510012.
