Frequency scanning leaky wave antenna for positioning and identification of RFID tags

A leaky-wave antenna showing the capability to frequency scan the main beam in the radio frequency identification (RFID) band from 2.40 GHz to 2.50 GHz is presented in this paper. The proposed antenna is based on a half-mode microstrip line working with its main leaky-mode. The dispersive response of this leaky-mode can be designed to operate in the RFID band, by properly choosing the substrate and dimensions of the microstrip line. Indeed, the control over the radiated pointing angle θ_RAD depending on the frequency, possibilities to address the incoming signal from the RFID tag. A parametric study is performed in this paper to illustrate the design methodology for this application. Moreover, the use of a totally planar structure allows to obtain a low-cost, low-profile, simply feeding, and easily integrable leaky-wave antenna for high-gain beam-scanning applications. In order to validate the proposed design, results obtained using commercial full-wave software are presented, demonstrating the operation principle and design flexibility of this leaky-wave antenna.