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A wideband microstrip forward-wave coupledline coupler with high coupling value is presented. Compared with the conventional edge-coupled microstrip forward-wave coupler, this symmetrical structure, consisting periodic shunt stubs between the two coupled-lines, achieves wider operating bandwidth and larger coupling level. To characterize this structure, the equivalent circuit model is established and verified by measurement and fullwave results. The designed and fabricated prototype is a 0-dB forward-wave coupler with 0.6 mm stub length. This coupler exhibits a coupled amplitude balance of±2 dB, good matching (15 dB) and at least 15dB isolation between adjacent ports over a wide bandwidth of 66% from 2 GHz to 4 GHz centered at 3 GHz. The coupled-line length and width of the proposed structure are approximately λg/2 and λg/13, respectively, which makes it more compact than the conventional forward coupled-line couplers.