Arbitrary power division quadrature branch-line coupler with harmonic suppression

摘要

A planar branch-line coupler with arbitrary power division and harmonic suppression is proposed. A novel offsetting double-side parallel-strip T-section is used for designing the coupler. To verify the design procedure, a prototype operating at 1.76 GHz with 10 dB power division ratio and a stopband up to nearly four times of the center frequency is simulated, fabricated and tested. The measured results agree well with the simulated ones.