A Compact Millimeter-Wave Planar Directional Coupled Crossover With a Wide Bandwidth
A compact planar directional coupled crossover with a wide fractional bandwidth is proposed in this letter, which is composed of overlapping planar 3-dB couplers based on the substrate integrated waveguide (SIW) and stripline techniques. In the proposed structure, the TE10 mode and TEM mode can be transmitted simultaneously without any interaction, which is helpful to design and integrate the SIW