Design of a stripline-structured hybrid based on LTCC technology

Hybrid is one of the most important microwave devices, whose miniaturization is a hot topic nowadays. According to the design principle of single-branch coupling line of directional coupler, factors that influence coupling coefficient and isolation are analyzed. Based on LTCC and HFSS, a novel stripline-structured hybrid is demonstrated in this paper, the isolation of which is less than -35dB and with dimension 3.2mm×3mm×1.2mm. Goal of miniaturizing the hybrid is finally realized.