Isolation improvement using CMRC for MIMO antennas

In this paper, a compact microstrip resonant cell (CMRC) is proposed to improve isolation of antenna elements in the design of multiple-input multiple-output (MIMO) antennas. The MIMO antenna used for studies consists of two symmetrical L-shaped planar inverted-F antenna (PIFA) elements placed at a distance of 16.2 mm on a printed-circuit board (PCB). A single-layer CMRC is etched on the PCB between the PIFA elements to improve isolation between them. Computer simulation is used to study and design the MIMO antenna. Results show that the CMRC can increase isolation between the two PIFA elements by 10 dB in the 2.4-GHz WLAN band. The envelope correlation coefficient (ECC) is about 0.0005 to 0.0035 over the frequency band.postprin

Compact Orthogonal Wideband Printed MIMO Antenna for WiFi/WLAN/LTE Applications

YesThis study presents a wideband multiple-input-multiple-output (MIMO) antenna for Wifi/WLAN/LTE applications. The antenna consists of two triangular patches as the radiating elements placed orthogonally to each other. Two T-slots and a rectangular slot were etched on the ground plane to improve return loss and isolation. The total dimension of the proposed antenna is 30 x 30 mm2. The antenna yields impedance bandwidth of 101.7% between 2.28 GHz up to 7 GHz with a reflection coefficient of < -10 dB, and mutual coupling of < -14 dB. The results including S-Parameters, MIMO characteristics with analysis of envelope correlation coefficient (ECC), total active reflection coefficient (TARC), capacity loss, channel capacity, VSWR, antenna gain and radiation patterns are evaluated. These characteristics indicate that the proposed antenna is suitable for MIMO wireless applications

A Reconfigurable MIMO Antenna System for Wireless Communications

A reconfigurable antenna system is proposed to improve data throughput limitations in multiple input multiple output wireless communication systems in this investigation. The4×4 MIMO antenna is designed to operate in the 2.4 and 2.6 GHz for  Wireless  Local  Area  Network  (WLAN)  and  Long  TermEvolution (LTE) applications. The system’s radiation pattern re-configurability is  realized by  using the  microcontroller-drivenPIN diode switching concept. Simulations and measurements exhibited good agreements for the single, 2×2 MIMO and 4×4MIMO configurations. The antenna is operational between 2.387to 2.628 GHz, while the simulated and measured reflection coefficients are at least -24.3 dB. All configurations produced anarrow beam forward radiation, while the envelope correlation coefficient (ECC) and diversity gain for the two MIMO configurations are below 0.5 and at least 9 dBi, respectively

Low-profile and closely spaced four-element mimo antenna for wireless body area networks

A compact four-element multiple-input multiple output (MIMO) antenna is proposed for medical applications operating at a 2.4 GHz ISM band. The proposed MIMO design occupies an overall volume of 26 mm × 26 mm × 0.8 mm. This antenna exhibits a good impedance matching at the operating frequency of the ISM band, whose performance attributes include: isolation around 25 dB, envelope correlation coefficient (ECC) less than 0.02, average channel capacity loss (CCL) less than 0.3 bits/s/Hz and diversity gain (DG) of around 10 dB. The average peak realized gain of the four-element MIMO antenna is 2.4 dBi with more than 77 % radiation efficiency at the frequency of interest (ISM 2.4 GHz). The compact volume and adequate bandwidth, as well as the good achieved gain, make this antenna a strong candidate for bio-medical wearable applications

Performance evaluation of 2-port MIMO LTE-U terminal antenna with user’s hand effect

This paper presents the performance evaluation of 2-port MIMO antenna for LTE-U sub 6 GHz band. The evaluation focuses on the effect of user’s hand in a uniform environment and the analysis were carried out on simulation and measurement data of antenna ports. Results show that the highest performance of the design is on the frequency range from 4.5 GHz to 5.5 GHz, and the ports have low envelope correlation coefficient (ECC) less than 0.16 in both cases of without and with user’s hand. However, the presence of the user’s hand reduces mean effective gain (MEG) of ports and diversity combining gain by more than 1.6 dB compared with no-hand case. The multiplexing efficiency is around 81% and reduced by the presence of the user’s hand to 55%. Despite this reduction; the design shows high spatial multiplexing capability in both cases. The capacity carried by the second transmission eigenmode is about 39% from the total capacity under water-filling algorithm transmit power allocation

High Isolation Wideband MIMO Antenna without Decoupling Technique for IoT Applications

This paper presents a method a high isolation wideband MIMO antenna without using any decoupling technique. This is achieved by transforming a strip line to a 1 ×2 MIMO antenna using Hilbert transform and Defected Ground structure is used in the antenna to resonate the antenna in for IOT and&nbsp; 5G sub-6 GHz bands. The proposed antenna has a size of 50 × 49.8 × 1.6 mm&nbsp;3&nbsp;and operates in the frequency band of 4.6 GHz to 5.94 GHz. The antenna simulated in ANSYS HFSS showed that its parameters Envelope correlation coefficient (ECC), Total Active Reflection Coefficient (TARC), Diversity gain (DG) and Channel Capacity Loss (CCL) are less than 0.04, -25 dB, 9.98 to 10 dB and less than 0.4 bits/s/Hz respectively. The radiation pattern of the antenna in both E-plane and H-plane has been simulated which the uniform distribution of power in the space

Study of multiple antennas with defected ground slot for low-band LTE application

This study is focused on highly coupled multiple antennas with defected ground slot techniques. Two Printed Inverted-F Antenna (PIFA) are positioned at the top edge of chassis symmetrically. Both antennas are operating at low-band Long-Term Evolution (LTE) with center frequency, 829MHz. Rectangular defected ground slot is implemented to reduce the coupling effect between the antennas on the ground plane of the small chassis. Parameter study of the rectangular defected ground slot is studied with different width, W and length, L. Furthermore, the optimized dimensions of rectangular defected ground slot, W and L are simulated and presented. The optimized defected ground slot reduced the mutual coupling up to -4.5 dB. The envelope correlation coefficient (ECC) achieved less than 0.5. The ground plane of the multiple antenna structure has been further investigated by introducing another slot with a gap of 1mm between them. The achieved result is not significant in term of S-parameter and ECC compared to single defected ground slot

Compact quad-element high-isolation wideband mimo antenna for mm-wave applications

This paper presents a multiple-input multiple-output (MIMO) antenna system for millimeter-wave 5G wireless communication services. The proposed MIMO configuration is composed of four antenna elements, where each antenna possesses an HP-shaped configuration that features simple configuration and excellent performance. The proposed MIMO design can operate at a very wideband of 36.83-40.0 GHz (measured). Furthermore, the proposed MIMO antenna attains a peak gain of 6.5 dB with a maximum element-isolation of -45 dB. Apart from this, the MIMO performance metrics such as envelope correlation coefficient (ECC), diversity gain, and channel capacity (CCL) are analyzed, which demonstrate good characteristics across the operating band. The proposed antenna radiates efficiently with a radiation efficiency of above 80% at the desired frequency band which makes it a potential contender for the upcoming communication applications. The proposed design simulations were performed in the computer simulation technology (CST) software, and measured results reveal good agreement with the simulated one

Metamaterial based design of compact UWB/MIMO monopoles antenna with characteristic mode analysis

In this article, a novel metamaterial inspired UWB/multiple-input-multiple-output (MIMO) antenna is presented. The proposed antenna consists of a circular metallic part which formed the patch and a partial ground plane. Metamaterial structure is loaded at the top side of the patches for bandwidth improvement and mutual coupling reduction. The proposed antenna provides UWB mode of operation from 2.6-12 GHz. The characteristic mode theory is applied to examine each physical mode of the antenna aperture and access its many physical parameters without exciting the antenna. Mode 2 was the dominant mode among the three modes used. Considering the almost inevitable presence of mutual coupling effects within compact multiport antennas, we developed an additional decoupling technique in the form of perturbed stubs, which leads to a mutual coupling reduction of less than 20 dB. Finally, different performance parameters of the system, such as envelope correlation coefficient (ECC), channel capacity loss (CCL), diversity gain, total active reflection coefficient (TARC), mean effective gain (MEG), surface current, and radiation pattern, are presented. A prototype antenna is fabricated and measured for validation