Dual-Band Rat Race Coupler with Different Power Division Ratio sat Two Bands

In this manuscript, a design guideline for dual-band rat- race coupler with two different power division ratios has been provided. The dual-band conditions are established based on the electrical nature of the coupler itself and the dual-band C-section coupled line instead of using a dual-band equivalent transmission line. The design equations are solved numerically to obtain the electrical parameters of the proposed coupler. A design example has been provided to validate the proposed concept.