Two- and Three-Way Filtering Power Dividers With Harmonic Suppression Using Triangle Patch Resonator

Abstract

This paper presents a new approach to design filtering power dividers (FPD) with regular triangle patch resonator (RTPR). According to the electric-field (E-field) distributions of the resonator modes, the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> and TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> modes have been selected to realize two- and three-way power dividers respectively, showcasing the flexible characteristic of the RTPR. Afterwards, an in-phase multiway excitation scheme for the RTPR is developed to well excite the designated modes and suppress multiple spurious modes, simultaneously. Subsequently, to further reject the harmonics so as to extend the upper stopband greatly, shorting posts are deployed at the locations with null electric field distribution for the specified operation mode. Ultimately, to validate the design concept, a two-way and a three-way second-order FPD employed at TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f_{10}= 1.27$ </tex-math></inline-formula> GHz) with fractional bandwidth (FBW) of 7% and at TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f_{11}= 2.2$ </tex-math></inline-formula> GHz) with FBW of 4.5% are designed and measured. The measured results of the two fabricated circuits well agree with the simulated ones. Results indicate that both of the two FPDs exhibit properties of good port-to-port isolation, high selectivity with transmission zeros near both sides of the passband, as well as wide stopband extended to 3.35 and 2.9 times of fundamental operation frequencies, respectively.