2-Dipoles Circularly-Polarized Antenna Integrated in Lamp Holder for Fixed RFID Reader

The paper presents a solution to integrate a circularly polarized antenna in a tracklight housing that contains both a lamp and a UHF-RFID reader. The antenna is located outside the tracklight housing since the cylindrical lamp holder is metallic and small in terms of wavelength, and there is no space enough inside it. Furthermore, the antenna does not interact with the lamp, so no specific lamp is required. The solution makes use of a standard print-circuit-board fabrication technique combined with a low-cost metal sheet cavity, that can be also drilled for aesthetical reasons. An antenna prototype has been designed for the North America market. The measurements showed a reflection coefficient less than -15dB and a gain greater than 6dBi in the band of interest (902-928 MHz).