A Compact Highly Efficient Hybrid Antenna Array for W-Band Applications

A W-band hybrid array with a compact size and a high efficiency is presented. With the aid of the joint design of the series-shunt feeding network and substrate integrated waveguide (SIW) blocked slots array, the array with 16 × 56 slots can be divided into eight areas, and then the bandwidth of impedance, gain, and radiation pattern can be improved effectively. Moreover, it has both the advantages of low profile over traditional SIW planar array and low loss over traditional air-filled rectangular waveguide (ARW) slot array. Due to the utilization of back-feeding technology of the proposed hybrid array instead of planar SIW divider, it could save a lot of area for radiating energy and lowering the insertion loss, thus resulting in the gain values higher than 30.7 dBi during the entire operational frequency coverage. It is corresponding to the total efficiency of 26.5%, which is higher than the traditional W-band SIW array due to the usage of the back feeding to conserve the radiation acreage and reduce the insertion loss. By designing the SIW slots array and series-shunt feeding network simultaneously, low sidelobe level characteristics of -16 and -20 dB in E- and H-planes have been successfully accomplished, respectively.