{'fraction_non_alphanumeric': 0.0387736699729486, 'fraction_numerical': 0.013525698827772768, 'mean_word_length': 6.025316455696203, '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}}
High‐efficiency cross and linear‐to‐circular polarization converters based on novel frequency selective surfaces

Most high‐efficiency polarization converters in literatures are based on reflective structures. Here we report the designs and experiments of high‐efficiency transmissive polarization converters using novel compact frequency‐selective surfaces (FSSs). By combining the common dipole and square ring based band‐pass FSSs, a novel FSS can be generated, whose high‐efficiency pass bands and transmissive phases for two orthogonal polarizations can be tuned by changing the dimensions of the FSS structure. As demonstrations of the concept, a transmissive cross polarization converter (a half‐wave plate) and a transmissive linear‐to‐circular polarization (LP‐CP) converter (a quarter‐wave plate) are designed and tested, respectively. Simulated results show that the polarization conversion ratio over 90% for the transmissive cross‐polarization converter is from 18.5 to 23.5 GHz, about 23.8%, and the 3‐dB LP‐CP conversion bandwidth is 19.6%. Experiments are carried out to validate both designs.