Reconfigurable antenna design approach for mobile applications and a technique for harmonics suppression

A design procedure for reconfigurable mobile antenna module is presented. A tuneable antenna, including a varactor diode placed at specific position over the radiating slot, was fabricated and tested over several targeted frequency bands (centred at 1.7, 1.8, 1.9 and 2.04 GHz) and their harmonics. A limitation of the tuneable antenna is its non-linear behaviour at the transmitter. A method to measure the radiated power from an active antenna (AA) at fundamental and harmonic frequencies is introduced to suppress the harmonic radiations of the active antenna. The experimental results on the received power show a very good capability for harmonic suppression.