This research proposes a compact indirect slot-fed wideband patch array antenna for a missile seeker application. The proposed single antenna consists of three dielectric layers for a radiator, an air substrate-integrated waveguide (SIW) cavity, and an indirect feeding network. The rectangular patch is used as a radiator on the first substrate layer, and the air SIW cavity (ASIWC) is employed to obtain high directivity and low mutual coupling characteristics in the second substrate layer. In the third layer, an indirect feeding structure is used to achieve the wideband characteristics in the Ka-band. The single element is extended to a 4 × 1 linear array with fabrication, and the fabricated array characteristics are measured in a full anechoic chamber. The measured operating fractional frequency bandwidth is 9.2%, and the measured array gain is 11.7 dBi at the bore-sight direction (θ0 = 0∘).

In recent years, efforts have been made to replace rod-shaped monopole antennas with planar antennas exhibiting an omnidirectional radiation pattern. In this paper, we describe the design, fabrication, and testing procedures of a dual-band planar antenna that can replace a monopole antenna used in wireless local area network (LAN) routers. The proposed antenna consists of a square metal patch, square ring, and shorting vias on a multilayer printed circuit board to induce 2.4 GHz and 5 GHz dual-band resonance and omnidirectional radiation patterns. The antenna design is optimized using a 3D full-wave simulation software, and an antenna sample is prepared using the printed circuit board fabrication process. The antenna sample is tuned using a copper tape to resolve the operation frequency mismatch, and its performance is tested using a network analyzer and an anechoic chamber. Furthermore, the antenna sample is installed in a commercial wireless LAN router, and its signal reception is analyzed in an actual wireless communication environment to verify its applicability.