Reconfigurable antenna design by using pin diode

Abstract

The concept of a reconfigurable of dipole and fractal dipole antennas were investigated to vary the frequency that is operated within 0.9GHz and 5GHz by changing the switches to ON or OFF mode by controlling PIN Diode switches. The fractal structure is used in antenna designs because of miniaturization and the dipole antenna is one of the omnidirectional that can be easily designed. The 4, 5 and 6 series dipole and fractal dipole was investigated and compared. Both antenna designs operated at almost the same frequencies and the radiation pattern. However, the return loss, directivity and gain were performed differently. The simulation result shows that the directivity and gain of fractal dipole was performed better than dipole . A 5 series dipole and fractal dipole have been selected to be fabricated on the FR4 microstrip board with £ r- 4.7 and thickness of 1.6 mm. The simulation results for the antenna were then compared with measurements, to show that the frequency can be varied by controlling the switches mode. The 5 operating frequencies were performed for both results. Thus 5 series dipole shows that the simulated operating frequency has shifted to the right from one frequency to another from 22%, 27%, 42% and 70% while the measured operating frequency has shifted from 22%, 39%, 42% and 100% between the 0.9 GHz and 5 GHz.