A Wideband Substrate Integrated Waveguide-Fed Open Slot Antenna

In this article, we introduce a new structure of an open slot antenna excited by a substrate-integrated-waveguide (SIW) feed to obtain a wide bandwidth of about 60%. Different from conventional slot antennas, two short sides of the slot are open which do not connect to any metal. To excite the open slot, an SIW section is used as the feed. In this way, the antenna is constructed on a single laminate which includes the feeding structure and the radiator. The open slot structure serves as a single-mode resonator with a low Q-factor and, thus, contributes a much wider bandwidth than that of conventional slot antennas and simultaneously maintains stable radiation performance. Intensive parametric studies were implemented to provide a design guideline. To verify our design, antenna prototypes were fabricated and measured. The measured results validate that the antenna achieves a wide impedance bandwidth of 59.3% from 50.8 to 93.6 GHz. Meanwhile, the radiation patterns keep stable over the entire operating frequency band. This new type of slot antenna with wide bandwidth and planar structure is a good candidate for mmW applications.