Experimental validation of minimum variance unbiased estimator of structural scattering Coefficient for an RFID antenna using linear model

It has been established that there is residual scattering from an antenna even though it is conjugately matched to its load impedance. This residual scattering is called as structural scattering and defined as a contribution to the total scattering from an antenna. The structural scattering is characterized by a structural scattering coefficient, A_s, and is dependent on the antenna structure, material, and shape. Though the structural scattering coefficient has been investigated for some antenna structures in the literature, there is no work proposing and performing the actual measurements of this value. In this paper, we propose a minimum variance unbiased estimator to estimate the structural scattering coefficient for an RFID bowtie dipole and we compare our results with the well-known method for theoretically calculating this value. We have focused our work on RFID since it relays on scattering for communication. However, the work is generic and applies to any antenna system.