{'fraction_non_alphanumeric': 0.013123359580052493, 'fraction_numerical': 0.0, 'mean_word_length': 5.366666666666666, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A physical bound on high impedance surfaces

A high surface impedance can be achieved in a limited frequency band by using composite structures. Based on the principles of causality, passivity, linearity, and time translational invariance we demonstrate that this bandwidth is bounded by the thickness and magnetic polarizability per unit area of the structure at normal incidence.