A W-Band, Low-Cost and High-Efficiency Antenna Array Using Multilayer SIW-to-SIW Transition With Leakage-Suppressing Scheme

In this communication, a W-band $8\times16$ substrate integrated waveguide (SIW) slot array antenna is proposed, which is designed to be low cost and high efficiency. The antenna utilizes a multilayer SIW-to-SIW transition with a double-side mushroom-like electromagnetic bandgap (EBG) structure to improve the performance of the conventional transition and suppress energy leakage. The antenna is composed of a radiator on the top layer printed circuit board (PCB), a power divider on the bottom-layer PCB, and the multilayer SIW-to-SIW transition at the end of the feeding network. The EBG is loaded on the middle layer between the radiator and power divider to avoid the propagation of the electromagnetic wave in an undesired parallel plate created between bonding layers, which reduces the insertion loss and improves the integration of the antenna. To validate the proposed design, an array antenna based on the normal PCB technology is fabricated and packaged in a metal box. The measured results demonstrate that the $8\times16$ antenna achieves an impedance matching bandwidth of 91.2-96.7 GHz and a peak boresight gain of 24.5 dBi at 94 GHz. Moreover, the ratio of the radiation aperture to the overall footprint is up to 80.2%, and the measured efficiency is 38.8%. The presented array antenna also has the advantages of being low cost, compact, and reliable.