A simplified design scheme for stubs loaded planar dual‐frequency microstrip crossover

In this article, design of a planar dual‐band crossover circuit is proposed. The design utilizes the symmetry of the circuit for the simplified even‐odd mode analysis. Derived closed form expressions are readily able to account for the type of stubs used in the design. Evaluation of the proposed crossover circuit and the corresponding expressions demonstrate that the design is able to achieve a considerably wide range of frequency ratios (1.8‐4.6). Two prototypes have been developed on Roger's 5880 substrate with the design frequencies of 1/2 and 0.5/2 GHz and a very good agreement between the measured and electromagnetic simulated results validate the design scheme.