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This letter introduces a new 3 dB branch line coupler for wideband applications. The wideband matching property of the coupler with four λ/4 open circuited coupled lines is briefly derived. The coupler with a suspended microstrip and microstrip line structures has been simulated with HFSS and fabricated. Measurement results show insertion loss better than 3.6 dB with a power imbalance of 0.5 dB; return loss and isolation characteristics both better than 20 dB over 49% fractional bandwidth.