A frequency-diverse metamaterial cavity antenna (FDMCA) that can be used for the microwave coincidence imaging is proposed in this letter. The proposed FDMCA is a slot antenna array excited by a metamaterial-based cavity, which can generate diverse radiation patterns at different frequencies. The average electric-field variation (AEV) is introduced to forecast the correlation coefficients of radiation patterns generated by the antenna. The lower the correlation coefficients are, the better the quality of the reconstructed image is. To verify the validity of the AEV and the superiority of the FDMCA, a disordered-structure-based cavity antenna (DSCA) and a lumpy-floor-based cavity antenna (LFCA) are also presented for comparison. Performances of the FDMCA, including the reflection coefficient, the radiation efficiency, and the correlation coefficients, are evaluated too. Microwave coincidence imaging experiments using the DSCA, LFCA, and FDMCA are carried out under the same condition and the target image can be reconstructed with high quality. The comparison of different imaging results illustrates the feasibility and superiority of the FDMCA. All results are validated through the simulations and measurements.

中文翻译：

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用于微波重合成像的分频超材料腔天线

在这封信中提出了一种可用于微波符合成像的分频超材料腔天线（FDMCA）。所提出的 FDMCA 是一种由基于超材料的腔激发的缝隙天线阵列，它可以在不同的频率产生不同的辐射模式。引入平均电场变化（AEV）来预测天线产生的辐射方向图的相关系数。相关系数越低，重建图像的质量越好。为了验证 AEV 的有效性和 FDMCA 的优越性，还提出了基于无序结构的腔体天线 (DSCA) 和基于块状地板的腔体天线 (LFCA) 进行比较。FDMCA 的性能，包括反射系数、辐射效率、和相关系数，也被评估。使用DSCA、LFCA和FDMCA的微波符合成像实验在相同条件下进行，可以高质量地重建目标图像。不同成像结果的对比说明了 FDMCA 的可行性和优越性。所有结果都通过模拟和测量得到验证。