Characteristic mode tracking plays a determining role in the correctness of the characteristic modes (CMs) results. The reliable modal tracking methods are usually either complex or have high computational time. Hence in this study, these challenges are overcome by supplementary algorithms as a novel solution to reduce the drawbacks of using mono‐structural algorithms. Therefore, a very simple algorithm is suggested as the main core of modal tracking, Then, the trajectory monitoring algorithm, error amender algorithm and decision‐maker algorithm are appended to improve the performance. The main core is the priority correlation‐based algorithm (PCA). When PCA cooperates with one of the proposed initial filters, CMs can be fast‐tracked but the results are not entirely correct. To increase accuracy, post‐processing analysis is suggested to detect errors and then correct them. Also, the post‐processing block can reduce Modal Tracking Algorithm computations due to using a new adaptive frequency step size. The CMs of three structures are tracked to demonstrate the performance of the proposed method. In addition, the critical decisions of modal tracking algorithm are investigated in detail.

This paper proposes a new framework based on the characteristic modes analysis (CMA) to design polarization conversion metasurfaces (PCMs). This approach relies on the information inferred from the characteristic currents of the dominant modes (DMs). To demonstrate the advantages of this strategy, a multi-functional PCM is designed for the X-band frequencies. Besides, this paper expands and develops the characteristic mode rotation (CMR) method to reveal the intrinsic behavior of PCMs in a new manner. In addition, the extended CMR method is utilized for the first time to investigate the physical concepts behind polarization purity and angular stability at the resonance frequencies. Finally, a prototype of the designed polarizer is fabricated and its reflection coefficients are measured. A great agreement between simulation and measurement results is obtained.

This paper proposes a new framework based on the characteristic modes analysis (CMA) to design polarization conversion metasurfaces (PCMs). This approach relies on the information inferred from the characteristic currents of the dominant modes (DMs). To demonstrate the advantages of this strategy, a multi-functional PCM is designed for the X-band frequencies. Besides, this paper expands and develops the characteristic mode rotation (CMR) method to reveal the intrinsic behavior of PCMs in a new manner. In addition, the extended CMR method is utilized for the first time to investigate the physical concepts behind polarization purity and angular stability at the resonance frequencies. Finally, a prototype of the designed polarizer is fabricated and its reflection coefficients are measured. A great agreement between simulation and measurement results is obtained.