Novel Coupled Line 180 $^{\circ}$ Hybrid With Non-Interspersed Input and Output Ports

This paper presents a novel coupled line 180^° hybrid with non-interspersed input/output ports. With the combination of a weak coupling parallel coupled line and strong coupling trans-directional coupler, a non-interspersed input/output ports coupled line 180 ^° hybrid is obtained by using printed circuit board fabrication process, and reduced substrate area is achieved. The proposed hybrid owns the features of reducing the complexity of dc biasing for the next-stage active circuits. Moreover, it requires no bond wires, via-holes, or multilayer structures. The formula of the proposed hybrid is derived, and the characteristics of the hybrid are analyzed. Two prototypes are designed to verify the concept. One is arranged with the two couplers perpendicular to each other, and the other is constructed with the two couplers arranged in a line. The measured results are in good agreement with the simulated ones.