Design of Frequency-Reconfigurable Printed Monopole Antenna Using Capacitive Loading

In this work, a novel frequency-reconfigurable printed antenna is proposed. The structure consists of a capacitively loaded loop (CLL) introduced into the near field region of a printed monopole antenna to create multifrequency behavior. The frequency agility was realized by integrating a lumped capacitor between the CLL and the ground plane. A tuning range of 0.654-0.886GHz is successfully achieved when varying capacitance values from 0.5 to 4pF covering LTE and GSM bands while keeping the operating frequency F
₁
=2.65GHz of the reference antenna changeless. The simulated results of return loss, surface current distribution and radiation patterns are presented and discussed.