The Quadrature 90° Hybrid Miniaturization at 24 GHz Band

In this paper, a design of a miniaturized microstrip quadrature 90° hybrid coupler using printed transmission lines and printed capacitors is presented. In order to perform the miniaturization process, the conventional quadrature 90° hybrid coupler planar arms are replaced with equivalent shorter ones which include printed capacitors in each junction of the component. The proposed coupler structure is designed to operate in the 24 GHz - 24.25 GHz band which is used for communication and radar systems. In this design, the main challenge in miniaturization was due to the coupling between the adjacent microstrip lines of the component. The proposed device area is 41% smaller compared to the conventional quadrature 90° hybrid coupler. The simulations were done using Ansys HFSS and Ansys Circuit software.