SIW-Fed Yagi Antenna and Its Application on Monopulse Antenna

Planar Yagi antennas are commonly hard to possess simple structure, high gain, and broad bandwidth at the same time. In this letter, a new substrate integrated waveguide (SIW)-fed Yagi antenna is proposed with nonplanar director element, and it achieves bandwidth of 25.7% and gain of 9.46 dBi at 10.0 GHz. Integrated of an SIW hybrid ring coupler, a Yagi monopulse antenna is designed. Measured gain of the sum pattern is higher than 13 dBi, whereas the maximum null depth of the difference pattern is lower than -20 dB in 9.4-10.05 GHz. This type of monopulse antenna presents an excellent candidate in directional-finding system.