Design of RFID Reader Antenna for Healthcare Applications

Abstract

An array based Reader antenna for RFID system having high gain with circular polarization (CP) is presented in this paper. Such antenna consists of two main radiation patches connected in parallel. The antenna is compact in size and is designed on a FR4 epoxy substrate with dielectric constant (􀀁r)of 4.4 and loss tangent of 0.02. The antenna is excited with an inset feed line and it operates in ISM band with resonant frequency of 2.4 GHz. It is capable of reading multiple RFID tags within its operating frequency range. The dimension of the antenna is 0.96λ×0.585λ×0.012λ, where λ represent the wavelength of the resonant frequency. The gain of the above antenna is 6.1 dB with a reflection coefficient (S11)of−17.4 dB. To investigate the performance of the proposed antenna, different optimization techniques are applied with experimental demonstration. The axial ratio value of the proposed antenna array is 0.3 dB which makes this antenna suitable candidate for healthcare applications.