Isolation Improvement Using Asymmetric Radiators and Ground Plane Diversity Mechanism in a Six-Element Uwb Mimo Antenna Design

Abstract

A compact six elements MIMO antenna is presented for UWB applications. The proposed MIMO array consists of non-identical monopole antennas with distinctive ground planes so as to nullify mutual coupling amid side-by-side elements. Also, by properly placing the antenna elements exploiting cross polarization diversity, a good isolation throughout the operating bandwidth is achieved. Moreover, two parasitic inverted L stubs in combination with small rectangular stubs are employed near the middleplaced radiators and corner placed radiators, respectively, in order to extend the frequency band and enhance the impedance matching. Results show a good reflection coefficient about −10 dB, a high isolation > 20 dB, an envelope correlation coefficients < 0.15, a high diversity gain equal to 9.3, and finally, a maximum value of efficiency for both used antenna elements which is about 78% and 60% with 6 and 5 dBi of gain, respectively. They validate the proposed MIMO antenna efficiency for UWB diversity applications.

Design of High Isolated 2 to 8 Ports MIMO Antenna for High Data Rate UWB Applications

“…Initially, a 4 × 4 MIMO antenna design is performed, employing cross-polarization diversity to verify its effectiveness on reducing mutual coupling. As shown in [11], a good impedance matching of about -20 with a good isolation of about 10, 12, 23 were achieved over the entire operating frequency band. Knowing that the highest value of isolation which is 23 corresponds to the antenna elements placed in a crossed from each other, which proves the effectiveness of the cross-polarization technique on meeting a high isolation amid radiators.…”

“…While for the second antenna (4×4 MIMO) that is studied in paper [10], in order to enhance isolation amid its radiators, a so-called Circular Ripple-Shaped decoupling structure is employed in combination with a matching structure to improve isolation as well as the impedance matching at the same time. Next, a design of a 6×6 MIMO antenna that is proposed in reference [11], is initiated to meet contemporary radio communication systems needs. The modeling of this antenna is based on the use of non-symmetrical monopoles with separate ground planes in such a way that the mutual coupling amid the along-sided radiators is cancelled.…”