Narrow-Wall-Fed Substrate Integrated Cavity Antenna at 60 GHz

Antennas with low cost, high gain, and high integration ability are highly demanded for millimeter-wave communications. When comparing with conventional planar antennas, such as patch arrays, which suffer from server loss and low efficiency, the substrate-integrate cavity (SIC) antennas exhibit better performances in terms of high gain, high efficiency, and wide operating bandwidth, especially in millimeter-wave frequency bands. In this chapter, the design and research progress of substrate integrated cavity antennas is reviewed. The fundamental broadband techniques for substrate integrated cavity antenna are discussed, including the impedance matching methods and multi-mode method. Selected state-of-the-art techniques of SIC antennas, including SIC backed slot antennas, patch loaded SIC antennas, and traveling-wave elements loaded SIC antennas have been reviewed and compared. In particular, the technique to excite a SIC using narrow-wall slot is elaborated, and furthermore a 2 × 2 array composed of narrow-wall-slot fed SIW at 60 GHz is exhibited as an example.