A novel topology for designing dual-band couplers with −3 dB coupling and a wide range of dual-band frequency ratios is presented. The proposed structure consists of two coupled-line sections connected by two uncoupled lines and four tapped stubs. This coupler can achieve a high frequency ratio of up to 5 by adjusting the impedance of tapped stubs. An experiment coupler operating at 0.7/2.6 GHz with a frequency ratio of 3.71 and −3 dB coupling was fabricated for demonstration.