## 1 Introduction  
LTE developed by third generation partnership project (3 GPP) is a fourth generation (4G) wireless standard that provides 10 times the speed of 3G network [1]. It is designed to provide IP-based data, voice, and multimedia streaming at a speed ranging from 100 Mbps to 1 Gbps. Because of this dramatic increase in capacity and speed of data transmission, multiple antenna techniques have gained overwhelming effects in the area of wireless communication throughout the last decade. However, designing of antennas for such a high-speed data transmission poses challenges in terms of isolation between antenna elements and the size of the antenna which may ultimately affect system performance. A considerable amount of work has already been done in the area of microstrip patch antennas (MPAs) but they suffer from low bandwidth [2] and metallic losses at high frequencies.  
Dielectric resonators when used as a radiator have low losses, high radiation efficiency, and high bandwidth as compared to the conventional MPAs [3]. Importantly, various modes can be excited with diverse radiation characteristics using a single dielectric resonator which makes it an appropriate alternative for multifunction applications [4].  
[PERSON] et al. for the first time gave the concept of a MIMO DRA and achieved 10 dB diversity gain [5] which is comparable with MIMO dipole array used in IEEE 802.11n, but no explicit design method is given in this paper. A dual-port MIMO design at 700 MHz for LTE Femtocell base station applications is proposed in [6] that achieved channel capacity up to 11.1 bps/Hz with excellent port isolation. In [7], the authors proposed a single element dual-port MIMO rectangular DRA at 2.6 GHz excited by two symmetric microstrip feed lines. Acceptable results have been obtained in terms of S-parameters, radiation pattern plots, correlation coefficient, mean effective gain, and diversity gain. In [8], the authors proposed rectangular DRA at 2.6 GHz, excited by coplanar waveguide and a coaxial probe and obtained reasonable results in terms of correlation coefficient and diversity gain.  
Antennas proposed in [5; 6; 7; 8] are designed for single-band MIMO operation. A lot of research studies have been presented on dual-polarized microstrip patch antennas but, their metallic losses at high frequencies become substantial. A compact and multiband DRA for mobile handheld devices for DVB-H, Wi-Fi, and WiMAX is presented in [9] using two dielectric resonators. However, there is large ground size and high mutual coupling values, especially at the higher band. Another dual-band DRA with MIMO characteristics reported in literature is in cylindrical form covering DCS and WLAN bands [10]. This design has good isolation but with large values of ground plane and DRA height.  
In this paper, a MIMO rectangular DRA with dual-band characteristics is reported using a single radiator to operate at 1.8 and 2.6 GHz bands for LTE applications. A rectangular shape is chosen because it has one more degree of freedom than cylindrical and two degrees of freedom than hemispherical DRAs. Lower frequency band of the proposed design may be termed as wideband as it covers three LTE bands 2, 3, and 9 simultaneously. The simulation of the presented MIMO antenna is performed with the help of Ansoft HFSS v 16.0 and a good agreement is found between the simulated and measured results.  
The remainder of this paper covers antenna geometry description in Section 2. Antenna design analysis including effect of electric field on mutual coupling will be presented in Section 3. Section 4 is dedicated to discuss results in detail and Section 5 concludes the paper.