{'fraction_non_alphanumeric': 0.03666361136571952, 'fraction_numerical': 0.02841429880843263, 'mean_word_length': 5.699386503067485, '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}}
Tunable Band‐Pass Filters Based on Varactor‐Loaded Complementary Split‐Ring Resonators on Half‐Mode Substrate Integrated Waveguide

Miniaturized band‐pass filters (BPFs) using backward wave propagation in the left‐handed (LH) band are proposed in this article. A half‐mode substrate integrated waveguide (HMSIW), complementary split‐ring resonators (CSRRs), and varactors are embedded on the same planar platform to implement the resonant‐type approach of metamaterial transmission line and tuning capability. The tuning of the passband frequency is generated by simple and single direct current (DC) voltages from 0 to 36 V, which are applied to each varactor on CSRRs. Different capacitance values and resonant frequencies are produced while maintaining a nearly constant absolute bandwidth and quality factor. About 6.5% tunability and 11.30% of 3‐dB fractional bandwidth is achieved around 2.30 GHz. The new electrically tunable BPFs are verified by a good agreement between the simulated and measured results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2458–2460, 2013