Compact Reconfigurable Patch Antenna for Wirelesss Applications

Abstract

A novel miniatured reconfigurable antenna for wireless applications using defective ground structure is proposed and studied. This proposed antenna generates eight different frequencies, operating at 2 GHz (IMT), 2.3 GHz (UMTS), 2.5 GHz (Wi-Fi), 2.7 GHz (Radio astronomy), 2.9 GHz (Weather radar), 4.2 GHz (Radio altimeter), 4.4 GHz (Radio determination), and 5.5 GHz (Wi-MAX) while maintaining overall compact size of 24 × 33 × 1.6 mm 3 using an FR-4 substrate having a permittivity of ε r = 4.4. The proposed reconfigurable antenna consists of three switches in the slots of the patch along with rectangular defects on ground surface and a microstrip feed line. The lumped elements are used in place of three switches in the simulation to get tuneable capacitance, which is responsible for frequency reconfigurability. It makes the antenna operate at eight useful bands. The structure shows the impedance bandwidths of 6.86%, 6.04%, 2.51%, and 2.73% with gains 5 dB, 4.8 dB, 6 dB, and 6.8 dB, respectively. The designed antenna can be easily integrated on modern communication devices. A prototype of the designed antenna is fabricated, and the simulation results are compared with measured values using PIN diode switches.