Antenna Efficiency Calculations for Electrically Small, RFID Antennas

Radio frequency identification (RFID) antenna efficiency is an important component of link budget design. A method of moments technique based on the summation of segment currents compares favorably with two different results obtained using the finite element method (radiation pattern integration and Wheeler cap). The efficiency of a resonant dipole was found to be proportional to the inverse square root of the conductivity. For a typical RFID meander line antenna in free space the relationship is more severe