Compact dual-polarized meandered dipole antenna with LC-balun integrated CPW-G feeding lines for UHF RFID applications

Abstract

This article presents a compact dual-polarized meandered dipole antenna with an LC-balun integrated coplanar waveguide with ground (CPW-G) feeding lines for ultrahigh frequency radio frequency identification handheld readers. It consists of printed +/- 45 degrees dipole antennas on an upper substrate with parasitic elements on a lower substrate, which is made by a fan-shaped meandered line. The feeders for the radiators are independently made up of a CPW-G line in supports and it is connected to the radiator by LC-balun. The proposed antenna has vertical and horizontal linear polarization, and it is fabricated on an RF-35 substrate and the size is 0.21 lambda(0)x 0.21 lambda(0) x 0.08 lambda(0) at 915 MHz. The peak gain and 10-dB impedance bandwidth are approximately 3.3 dBi and 12%, respectively. In addition, measured isolation between two radiators is approximately 32 dB at 915 MHz.