Ultra-Wideband Polarization Insensitive Angle Filter Based on ENZ Characteristics and Dynamic Antireflection Structures

Bandwidth expansion has always been an important dimension in investigating angle filters (AFs) and is critical for optical communication and radar detection. In this paper, the AF with strong selectivity is realized by using the epsilon-near-zero (ENZ) jump characteristic of YaBa2Cu3O7 material. At the same time, for both the TE and the TM waves in the range of 237~1000 THz, the transmissivity of the AF is stronger than 0.9 by using dynamic antireflection structures (AFSs). The transfer matrix method is suitable for theoretical calculation, and the impedance matching theory is introduced to analyze the features of the AF. The increment of the thickness of superconductor material can effectively enhance the selectivity of the AF structure, and the consequence is the attenuation of transmission performances. If the temperature is covered from 0 K to 85 K, the filtering performance higher than 0.9 can still be maintained for two polarization waves. For these explicit performances, the proposed design may provide a new idea for widening the frequency bandwidth of the AF.