Unidirectional Radiation Efficient Stacked Aperture Antenna for X-Band Application

Presented is a unidirectional slot aperture antenna for wideband operation, which is composed of two stacked bow-tie apertures backed by a metallic reflector. Parasitic parallel plate wave propagation is suppressed by shorting pins. The measured bandwidth defined by return loss < -10 dB is 27%. The radiation efficiency in this frequency range is about 85%.