scholarly journals Modified MIMO Cube for Enhanced Channel Capacity

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Lajos Nagy

This paper deals with the optimization of MIMO antenna elements' position in modified MIMO cube for getting maximal channel capacity in indoor environment. The dependence of the channel capacity on the antenna orientation was analyzed by simulations. We have also examined the effect of the frequency dependence of the antenna system (in case of conjugate matching and nonconjugate matching) for the channel capacity. Based on the simulation results in the created and measured antenna system, the antennas were at a right angle to each other. At the two chosen different structures, we measured the antenna parameters and the channel capacity. In this paper, we present the results of the measurements which clearly confirm our simulations. We will point out the differences between the two antenna structures.

2021 ◽  
Vol 36 (1) ◽  
pp. 55-60
Author(s):  
Qin Li ◽  
Yufa Sun ◽  
Hongyu Fang

In order to improve the channel capacity of communication equipment and reduce the size of antenna, an asymmetric coplanar strip (ACS) fed four-element UWB MIMO antenna with dual band notches is proposed in this paper. The antenna has a simple structure and a compact size of 37×37 mm². The antenna consists of four modifled staircase-shaped radiation elements and four floor on the same side. The antenna elements are placed vertically without additional decoupling structure, and the isolation less than -15 dB in the working bandwidth of 2.9-10.6 GHz can be obtained by using polarization diversity. In addition, the antenna has the notched characteristic of WiMAX and WLAN band. The antenna has good gain and low envelop correlation coefficient (ECC), and the simulation results agree with the measured results, which indicates that the antenna is suitable for UWB system.


2021 ◽  
Vol 36 (3) ◽  
pp. 282-294
Author(s):  
Asmaa Farahat ◽  
Khlaid Hussein

In this paper, a dual-band (28/38 GHz) linear antenna arrays of four and eight elements are proposed to work as a MIMO arrays for the 5G communication systems. Each element in the array is a dual-band Yagi-Uda antenna designed to operate at 28 and 38 GHz. The eight-elements array size has a total dimension of 79.4 mm x 9.65 mm excluding the feeding microstrip line. The maximum gain of the array is about 18 dB. The peaks of correlation at matched angles (PCMA) technique is applied to determine the direction of arrival for multiple incoming signals. The effects of phase noise and additive Gaussian noise on the error in the DoA estimation are studied showing good accuracy of the PCMA algorithm. Numerical and experimental investigations are achieved to assess the performance of both the single-element antenna and the eight-element MIMO linear antenna array. It is shown that the simulation results agree with the experimental measurements and both show good performance of the single antenna as well as the MIMO linear array system. The envelope correlation coefficient (ECC) and the diversity gain (DG) are calculated and the results show that the proposed MIMO antenna system is suitable for the forthcoming 5G mobile communications. The radiation patterns for single antenna and four-element array are measured and compared to the electromagnetic simulation results showing good agreement.


Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 871
Author(s):  
Kazuhiro Honda ◽  
Taiki Fukushima ◽  
Koichi Ogawa

This paper presents a multiple-input, multiple-output (MIMO) antenna system with the ability to perform full-azimuth beam steering, and with the aim of realizing greater than 20 Gbps vehicular communications. The MIMO antenna described in this paper comprises 64 elements arranged in a daisy chain array structure, where 32 subarrays are formed by pairing elements in each subarray; the antenna yields 32 independent subchannels for MIMO transmission, and covers all communication targets regardless of their position relative to the array. Analytical results reveal that the proposed antenna system can provide a channel capacity of more than 200 bits/s/Hz at a signal-to-noise power ratio (SNR) of 30 dB over the whole azimuth, which is equivalent to 20 Gbps for a bandwidth of 100 MHz. This remarkably high channel capacity is shown to be due to two significant factors; the improved directivity created by the optimum in-phase excitation and the low correlation between the subarrays due to the orthogonal alignment of the array with respect to the incident waves. Over-the-air (OTA) experiments confirm the increase in channel capacity; the proposed antenna can maintain a constant transmission rate over all azimuth angles.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 383
Author(s):  
Wazie M. Abdulkawi ◽  
Waqar Ahmad Malik ◽  
Sajjad Ur Rehman ◽  
Abdul Aziz ◽  
Abdel Fattah A. Sheta ◽  
...  

A compact four-element dual-band multiple-input and multiple-output (MIMO) antenna system is proposed to achieve high isolation and low channel capacity loss. The MIMO antenna was designed and optimized to cover the dual-frequency bands; the first frequency band is a wide band, and it covers the frequency range of 1550–2650 MHz, while the other frequency band covers the 3350–3650 MHz range. The measured wide-band impedance bandwidths of 1.1 GHz and 300 MHz were achieved in the lower and upper frequency bands, respectively. The proposed structure consists of four novel antenna elements, along with a plus-sign-shaped ground structure on an FR4 substrate. The overall electrical size of the whole dual-band MIMO antenna system is 0.3λ(W) × 0.3λ(L) × 0.008λ(H) for the lower frequency band. It achieved greater than 10 and 19 dB isolation in the lower and upper frequency bands, respectively. The antenna system accomplished an envelope correlation coefficient of |ρ|≤0.08 in the lower frequency band, while it achieved |ρ|≤0.02 in the higher frequency band. The computed channel capacity loss remained less than almost 0.4 bits/s/Hz in both frequency bands. Therefore, it achieved good performance in both frequency bands, with the additional advantage of a compact size. The proposed MIMO antenna is suitable for compact handheld devices and smartphones used for GSM (Global System for Mobiles), UMTS (Universal Mobile Telecommunications Service), WCDMA (Wideband Code Division Multiple Access), LTE (Long Term Evolution), 5G sub-6 GHz, PCS (Personal Communications Service), and WLAN (wireless local area network) applications.


Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kumar D. Rajesh ◽  
Babu G. Venkat

Abstract In this paper, six-port MIMO antenna is presented for 5G mobile handsets. The proposed six-port antenna array is designed by making four L shaped monopole slots at four corners and two at the middle side edges of the ground plane which is printed on the backside of 0.8 mm thick FR4 substrate. High isolation (>−18 dB) between any pair of antenna elements is achieved without deploying dedicated isolation enhancing mechanisms. The antenna is working from 3.4–3.6 GHz (LTE Band 42) with 200 MHz bandwidth in the 2:1 VSWR (−10 dB impedance bandwidth). The proposed six-port MIMO antenna array is fabricated and measured. Significant radiation efficiency is obtained from 70 to 74 % in desired band of operation. Further, the MIMO parameters such as Envelope Correlation Co-efficient (ECC), Channel Capacity, Channel Capacity Loss (CLL) and Total Active Reflection Co-Efficient (TARC) are calculated. The robustness of the antenna is estimated by analyzing the user hand effects and Specific Absorption Rate (SAR). The measured results are well agreed with the simulated results.


Author(s):  
Abdurrahman Rizki ◽  
Alloysius Adya Pramudita ◽  
Trasma Yunita

Multiple Input Multiple Output (MIMO) system is a technology that has the potential to be developed to increase channel capacity. The increase in channel capacity in the MIMO system is not only determined by the number of antennas, but is determined by the characteristics and arrangement of the antenna concept. This study identifies the effect of circular polarization on the MIMO antenna system on channel capacity. Co-polarization consists of a Left Hand Circular Polarization (LHCP) and Right Hand Circular Polarization (RHCP) configuration, while cross-polarization consists of an RHCP-LHCP configuration. The co-polarization of the antenna with the LHCP configuration results in an estimated channel capacity of 11,578 bps / Hz when it is at the lowest Signal to Noise Ratio (SNR) is 5 dB


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