Design of compact frequency reconfigurable planar invert‐F antenna for green wireless communications

Abstract

This study proposes a single frequency reconfigurable planar invert-F antenna (FRPIFA) using PIN diodes based on the changes of shorting pin positions. The single FRPIFA operates in four configurations which cover the bands of GSM 900/GSM 850, GPS 1575, GSM 1800/GSM 1900 and UMTS (Universal Mobile Telecommunication System) with peak gains of −7.24, 2.30, 2.98 and 3.53 dBi, respectively. Furthermore, a frequency reconfigurable multiple-input multiple-output (MIMO) antenna consisting of two single reconfigurable ones with a distance of half-wavelength is presented. By switching the PIN diodes, the reconfigurable MIMO antenna obtains four different configurations. For MIMO antenna, results of the operating bands, gains, radiation patterns are similar to those of the reconfigurable single one. The MIMO antenna achieves a high isolation with |S21| less than −20 dB in all operating bands. The simulated results of S-parameters of the antennas are in good agreement with measurements. The proposed compact single and MIMO antennas are suitable for green smart wireless communication systems.