Printed Planar Double Inverted-F Antenna with Large Frequency Reconfigurability Range

The use of frequency reconfigurable antennas is extremely important for Cognitive Radio (CR) systems. In this paper, we propose to study and design a multiband planar double inverted F-antenna (PIFA) with frequency agility characteristic. The proposed antenna is suitable for several applications. in fact, one varactor diode was integrated between the radiating element and the added floating ground plane. We apply a reverse voltage V on the varactor diode and we obtain more than three resonance frequencies with wide tuning ranges. Frequencies can be shifted from 700 to 1450 MHz and 1975 to 2800 MHz. The passive and active antennas were manufactured and measured. Simulations and measurements are presented and discussed.