Most reports in the published literature concentrated in the backward couplers, while little attention has been paid to forward couplers. In this paper, we propose a novel single-sectioned microstrip line forward coupler, which consists of parallel coupled lines and asymmetrical delay lines. The operation frequency is chosen as 2.45GHz. The simulation results show, by proper design of some structural parameters, such as the length of coupling lines and delay lines, the designed structure enables the coupler to enhance the coupling and directivity, as well as to avoid the enlargement size of the coupler owing to the introducing of the tapered lines. Based on the well-designed coupler above, we have further designed a multi-ports microwave network circuit. The tested and experimental results show the reliability of the forward coupler.
