High-Gain and Wideband Antenna Arrays: Introducing Three Patch Antenna Arrays to Show the Advantages of SPPWs Used in a Feed Network

Spoof planar plasmonic waveguides (SPPWs) are a new type of low-loss surface wave transmission line whose modes are tightly confined near the SPPWs. Spoof surface plasmon polaritons (SPPs) propagating in the SPPW can be efficiently converted into free-space radiation by high-efficiency antennas. In this article, three patch antenna arrays are introduced to show the advantages of SPPWs used in a feed network, such as low-insertion loss. The first patch antenna array is designed to illustrate the feeding mechanism by the SPPW. The second antenna array is designed directly based on the first for high-gain purpose; it is also fed by the SPPW. For comparison, the third one is a stacked patch array fed by the SPPW to improve bandwidth. All of the antenna arrays are operated in the K-band, and the experimental results validate the simulations of the proposed arrays. This idea provides a simple way to design high-gain antenna arrays and an avenue to extend the bandwidth of antenna arrays excited by SPPWs.