volume | PIER Journals

Abstract

In order to effectively reduce the loss of the filter, decrease its size, and improve its frequency selectivity, a miniature filter unit has been proposed. This unit offers enhanced frequency selectivity and facilitates adjustment of the center frequency. The filter unit is constructed by embedding a serpentine microstrip resonator in the upper metallic surface of a half-mode substrate-integrated waveguide (HMSIW). The center frequency of the filter unit is considerably lower than the cutoff frequency of the HMSIW, which contributes to the miniaturization of the filter. The center frequency of the filter unit can be adjusted solely by modifying the dimensions of the microstrip resonator, while the dimensions of the remaining components can be maintained at a constant value. A transmission zero has been incorporated into the upper resistance band with the objective of enhancing its frequency selectivity. A second-order filter with a center frequency of 3 GHz is accurately designed using this filter unit. The results demonstrate that a miniaturized filter with the desired center frequency and excellent performance can be rapidly achieved using this filter unit, which has potential applications in the 5G (sub-6G) band.

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Dr. Lianxin Li

Prof. Xiaohei Yan

Dr. Fupeng Wei

Dr. Guiqing Liao

Dr. Weijun Yv

Dr. Keyou He