Mutual Coupling Reduction Using Hybrid Technique in Wideband Circularly Polarized MIMO Antenna for WiMAX Applications

Abstract

In this paper, a novel wideband circularly polarized multiple-input multiple-output (MIMO) dielectric resonator antenna (DRA) has been proposed for worldwide interoperability for microwave access (WiMAX) applications. The mutual coupling (MC) between closely placed DRA units at 0.5λ has been significantly reduced by using a new hybrid technique. The exclusive features of the proposed MIMO antenna include wide impedance matching bandwidth (BW), broadband circular polarization (CP), and suppressed MC between the radiating elements. The first step of hybrid technique is the employment of parasitic patch at an optimized distance beside the conformal metal strip of the two identical rectangular DRAs in order to generate CP wave along with a wide impedance matching BW over the same frequency range. In the final step, the MC is suppressed significantly along with the broadband CP by placing the DRAs diagonally at an optimized position. The proposed MIMO antenna is the hybrid of the parasitic patch and the diagonal position of radiating elements. The CP BW offered by the proposed antenna is ∼20.82% (3.58-4.40 GHz) in conjunction with an impedance-matching BW of ∼38.51% (3.50-4.95 GHz). Moreover, MC less than −28 dB is achieved over the entire band and −26 dB at 3.89 GHz (minimum of the AR) through the hybrid technique. The prototype of the proposed antenna geometry is fabricated and measured. A good agreement has been attained between the simulated and measured results.

Design of Quad-Port Ultra-Wideband Multiple-Input-Multiple-Output Antenna with Wide Axial-Ratio Bandwidth

“…In [29,30], four-port antennas with smaller ARBW and Table 3 compares the performance of the designed quad-port MIMO antenna with other reported MIMO/diversity antenna geometries [20][21][22][23][24][25][26][27][28][29][30][31]. Large-size dual-port or triple-port antennas with small impedance bandwidth are reported in [20][21][22][23][24][25][26][27][28]. In [22], the antenna possesses poor inter-element isolation, but good 3-dB ARBW.…”

“…In [26], a compact dual polarized UWB MIMO antenna for access point applications was proposed, where a modified serpentine structure (MSS) decoupling element was implanted amongst the radiators to obtain high isolation. A wideband CP dielectric resonator-based MIMO antenna was suggested in [27], where isolation between the elements was enhanced by means of a parasitic patch and arranging the resonators diagonally. In [28], a compact three-port MIMO antenna comprising of one patch antenna and two dipole antennas was suggested, where the CP band was realized by means of truncated corners.…”

Isolation Enhancement of Closely Packed Dual Circularly Polarized MIMO Antenna Using Hybrid Technique

“…These techniques are mostly reported to reduce mutual coupling of LP antennas but the impact of these techniques on the axial ratio (AR) of the CP antenna has been rarely discussed. Certainly, some CP MIMO antennas have been reported for high gain [13], [14], wideband [15]- [17] and planar [18]- [20] applications. Similar decoupling techniques are adopted, such as power dividers [13], DGS [14], and parasitic elements [16], [17].…”

Dual‐band circularly polarized MIMO DRA for sub‐6 GHz applications

“…But advantages of CP in antennas swerved the researchers toward new domain of circularly polarized MIMO DRA. Very few articles 12‐18 have been reported in this domain. In Reference 12 the authors have proposed dual polarized triple band (2.21‐3.13, 3.40‐3.92, and 5.30‐6.10 GHz) MIMO DRA for WLAN/WiMAX applications.…”

“…In Reference 15, a dual port CDRA based MIMO antenna with dual sense polarization has been presented for WLAN applications. In Reference 16, a hybrid technique has been employed using a parasitic patch at an optimized distance beside the conformal metal strip of the two identical rectangular DRAs in order to generate CP wave. In Reference 17 two‐element CP‐DRA array has been implemented with electromagnetic band‐gap (EBG) structure etched into the ground plane of the microstrip patch transmission line.…”