A Novel Two-Layer Low-Profile 23-GHz Microstrip Array Fed by Slots in an SIW for Wireless Backhauling Applications

Abstract

This paper proposes a robust option for developing a new class of efficient and cheap antenna array based on patch array fed by substrate-integrated waveguide (SIW) through slot apertures for wireless backhauling applications. It consists in performing the feed network in SIW and the radiating structure in microstrip technology. The microstrip lines are coupled to the slots on the top wall of the SIW. Hence, it is demonstrated that the best alternative of the costly, heavy, and bulky rectangular waveguide feeder is SIW, which provides miniaturization, cost reductions, performance enhancements, and easy integration with patch array antennas. The experimental prototype presented in this paper demonstrates the efficiency of the design method and the feasibility of creating low-cost moderate-bandwidth millimeter-wave planar $8\times 8$ patch antenna array configurations in two stacked substrates to get ultracompact antenna module. The principle of achieving such high-quality antenna array is presented in detail along with experimental verification of theoretical results to validate the design procedure and demonstration of the feasibility of implementing the array by means of relatively inexpensive compact structures. The maximum gain is around 23 dBi at 22.4 GHz, the measured impedance bandwidth is 5%, and the efficiency is around 70%.