{'fraction_non_alphanumeric': 0.028543307086614175, 'fraction_numerical': 0.011811023622047244, 'mean_word_length': 5.201219512195122, '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}}
Positive-to-zero continuously tunable inter-resonator coupling structure for applications in filter array systems

This paper presents a novel positive-to-zero continuously tunable inter-resonator coupling structure for high Q substrate-integrated waveguide resonators. Two nearly nonmutually coupled distinct inter-resonator structures were integrated. One structure provides positive static inter-resonator coupling while the other composes a continuously tunable negative coupling. The negative coupling can be tuned to be large enough to cancel out the static positive coupling and create a near-zero inter-resonator coupling state. Using the proposed tunable structure, a second-order continuously tunable Butterworth filter has been designed and fabricated. The bandwidth of the fabricated filter can be tuned from 3% to 0% at 1.3 GHz. Similar tuning is possible for all frequencies within the frequency range 0.95 GHz ~ 1.6 GHz. The fabricated filter has been measured to have frequency tuning ratio of 1.7:1.