Dual-Mode Power Divider and its Application in Monopulse Antenna

In this brief, we propose a dual-mode power divider (PD) based on slow-wave SIW structure. The slow-wave structure is integrated to the SIW for obtaining filtering feature and a multifunctional PD with both in-phase and out-of-phase responses is designed by adopting different feeding mechanism. Then, the presented PD is applied to build a monopulse antenna with simple structure. A tapered patch is inserted into the center of the PD and excited through coupling for endfire radiation. When the PD works in in-phase mode, the even-mode E-field can be obtained at the end of radiator, resulting in the difference beam. When the PD works in out-of-phase mode, the odd-mode E-field can be obtained at the end of radiator, leading to the sum beam. The proposed monopulse antenna was fabricated and measured for validating the feasibility of the design approach. Measured results indicate that the sum and difference beams of the antenna are both realized in the same frequency range. This approach provides a straightforward way to design monopulse antenna, which can be applied in radar detection and tracking.