A Novel Harmonics-Suppression Coupled-Line Gysel Power Divider for Complex Terminated Impedances

Abstract

A novel symmetrical coupled-line circuit structure is proposed to design a kind of harmonics-suppression coupled-line Gysel power divider that has the advantages of a compact structure and complex source to load-terminated impedances. It consists of four pairs of coupled lines, three pairs of transmission line stubs, and two grounded isolation resistors. Based on the traditional even-and odd-mode technique, closed-form mathematical equations for both circuit electrical parameters and scattering parameters are obtained. For demonstration purposes, two typical simulation examples with realized physical dimensions in microstrip technology are presented, indicating equal power division, good return loss, perfect isolation, and harmonics suppression on three different frequencies or wide operating frequency band. Finally, two practical microstrip coupled-line Gysel power dividers are designed and fabricated to operate at approximately 1 GHz. Good agreement between the simulated and measured results verify the design.