Subwavelength 3rd-, 5th-, and 9th-Order Bandpass Filters with Excellent Frequency Selectivity due to Transmission Zeros of the Cross-coupled Triplet of Zeroth Order Resonators

摘要

PURPOSE: Subwavelength third-, fifth-, and ninth-order bandpass filters with excellent frequency selectivity due to transmission zeros of cross-coupled triplet of zeroth order resonators are provided to obtain a microminiaturized bandpass filter using an inductive coupling structure in which a series inductor and a parallel capacitor of CRLH zeroth-order resonators are mixed. CONSTITUTION: A first inter-digital line is connected to an input port. A second inter-digital line is connected to an output port. The first and second inter-digital lines face each other. An inductor line is connected through T-junction between the first and second inter-digital lines. A connection line has a complex coupling structure comprising a series inductor and a parallel capacitor.