A Simple Printed Antenna With Broadband Property And Omnidirectional Radiation Patterns Of Wire Dipole

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 microstripfed 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 0.3 lambda x 0.008 lambda, showing its effectiveness in many applications of small antennas.