A Tri-Band Mimo Antenna for Wlan/Wimax Application

Abstract

Abstract-A tri-band multiple-input-multiple-output (MIMO) antenna that covers all frequency bands required for WLAN and WiMAX applications is presented. Three resonant bands are achieved by a folded monopole with a compact size of 11.5 × 15.6 mm 2 . The MIMO system consists of two symmetrically placed monopoles. A stepped slot ended with an ellipse on the ground plane is etched to reduce the mutual coupling between the two monopoles. The overall dimension of this MIMO system is 50 × 50 mm 2 . The prototype of the antenna is fabricated and measured. Measured results show that the antenna's impedance bandwidth is 450 (18%), 350 (10%), 1200 (21.8%) MHz at the three resonant frequency points (2.5 GHz, 3.5 GHz, 5.5 GHz) with mutual coupling between the antenna elements less than −18 dB in whole frequency band, making this antenna a good candidate for portable application.

A Simple Tri-Band Mimo Antenna Using a Single Ground Stub

“…Several methods have been devised to design a solitary radiating structure to operate on a number of bands instead of supporting many applications dedicated antennas in a particular device. This leads to the evolution of antennas resonating at multiple frequencies [10][11][12][13][14][15][16][17][18][19]. A dual band dual polarized high isolation antenna offering more than 95% efficiency is proposed in [10].…”

A Compact Mimo Antenna With Improved Isolation for 3g, 4g, Wi-Fi, Bluetooth and Uwb Applications

“…A number of techniques for reducing the mutual coupling and improving the isolation between closely spaced MIMO antenna elements have been reported in recent years which employ electromagnetic bandgap structure (EBG), metamaterial or defected ground structure (DGS) [3][4][5][6][7][8][9][10]. EBG structures are periodic structures with band gap characteristics which help to improve the isolation between the antenna elements [3][4][5].…”

“…They help to miniaturize the overall size of the antenna but its constraint lies in design complexity and isolation over wide band. DGS has been widely used for improving the isolation by introducing defects in the ground plane [8][9][10]. These defects act as band stop filter as inductance and capacitance of the defect block the surface wave from one antenna to another [8].…”

“…These defects act as band stop filter as inductance and capacitance of the defect block the surface wave from one antenna to another [8]. The isolation is improved by 7 dB over the band by using a square ring DGS in a collated MIMO antenna [9]. A folded monopole MIMO antenna is designed with a stepped slot DGS and an elliptical-shaped DGS to reduce the mutual coupling less than −20 dB over the operating frequency band [10].…”

A Penta-Band Printed Monopole Antenna for Mimo Applications

“…In [14], a triple-band C-shaped printed monopole antenna for MIMO application covered 2.1-2.6, 3.3-4, and 5.4-6 GHz is reported. A Compact Triband Quad-Element MIMO Antenna Using SRR Ring for High Isolation is reported in [15]. A quad-band F-shaped printed slot antenna for WLAN and WiMAX MIMO system is reported in [16].…”