A simple printed antenna with broadband property and omnidirectional radiation patterns of wire dipole

Abstract

This letter presents a unique printed dipole antenna which can roughly cover an 80% fractional bandwidth (VSWR≤3), and especially possess the omnidirectional radiation patterns similar to those of wire dipole antenna at its all resonant modes. The antenna is simple with a microstrip-fed structure which it is just composed of two arms with each one forming the shape of a conventional “inset-fed” rectangular patch antenna. At the lowest operation frequency for VSWR=3, the antenna size is only 0.3λ×0.008λ, showing its effectiveness in many applications of small antennas.