Compact and Wireless 2.5-5 GHz Frequency Doubler for Harmonic RFID Applications

This paper presents a harmonic RFID tag with possible medical applications. The proposed topology consists on a wireless 2.5 to 5 GHz frequency doubler. It occupies only 32mm × 16 mm and is based on a Schottky diode together with two printed Planar Inverted-F Antennae (PIFA). The design, fabrication and characterization are presented, where the experimental measurements prove a successful behaviour with a measured conversion gain up to -30 dB when the tag is present.