A microstrip array antenna with omnidirectional pattern fed by CPW

Colinear array antennas constructed from coaxial elements such as sleeve dipoles or patch antennas using parasitic cylinders are employed as omnidirectional antennas in mobile communication. In microcellular and wireless LAN systems, simple, small-size, and low-cost antennas for base stations are desired. The paper proposes a base station antenna that satisfies these requirements. The proposed antenna configuration is a back-to-back narrow-width rectangular patch fed by a CPW. The experimental results for an element antenna and an array antenna are described. Good omnidirectional radiation pattern characteristics have been obtained.