scholarly journals Differences in User Influence on MIMO Handset Antenna Performance in Reverberation Chamber

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Juan D. Sánchez-Heredia ◽  
Paul Hallbjörner ◽  
Juan F. Valenzuela-Valdés ◽  
Thomas Bolin ◽  
Antonio M. Martínez-González

User influence on multiple-input multiple-output (MIMO) performance is studied for different dual antenna handsets specially designed to have good and bad MIMO performance. The study reveals that user influence can cause either improvement or degradation for different test objects, including a spread effect over the parameters. Differences in performance between good and bad handsets can be clear when they are measured without user influence, but become small under real person influence. This result illustrates the particular importance of user influence to characterize MIMO handsets.

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoming Chen ◽  
Jian Yang

Most of previous studies on diversity gains and capacities of multiantenna systems assumed independent and identically distributed (i.i.d.) Gaussian noises. There are a few studies about the noise correlation effects on diversity gains or MIMO capacities, however, by simulations only. In this paper, the maximum ratio combining (MRC) diversity gain and multiple-input multiple-output (MIMO) capacity including correlated noises are presented. Based on the derived formulas, measurements in a reverberation chamber are performed for the first time to observe the effect of noise correlations on diversity gains and MIMO capacities.


2019 ◽  
Vol 57 (2) ◽  
pp. 223
Author(s):  
Hoa Nguyen Thi Quynh ◽  
Sy Tuan Tran ◽  
Huu Lam Phan ◽  
Duy Tung Phan

A compact three-port metamaterial multiple-input-multiple-output (MIMO) antenna using complementary split-ring resonator (CSRR) loaded ground have demonstrated in order to miniaturize the size and improve the antenna performance. The antenna is designed on FR4 material and simulated by HFSS software. By loading CSRRs in the ground plane, the size reduction of 77% of the individual patch antenna element is achieved, which appeared to be the major reason for the obtained the compact MIMO antenna. Furthermore, the simulated results show that the proposed MIMO antenna achieves the total gain higher than 5 dB, the isolation less than -11 dB, the envelope correlation coefficient (ECC) value lower than 0.015, and the bandwidth of 100 MHz through the whole WLAN band from 2.4 GHz to 2.484 GHz, indicating promises for WLAN applications.


Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1321
Author(s):  
Amjad Iqbal ◽  
Ahsan Altaf ◽  
Mujeeb Abdullah ◽  
Mohammad Alibakhshikenari ◽  
Ernesto Limiti ◽  
...  

This paper presents an isolation enhancement of two closely packed multiple-input multiple-output (MIMO) antenna system using a modified U-shaped resonator. The modified U-shaped resonator is placed between two closely packed radiating elements resonating at 5.4 GHz with an edge to edge separation distance of 5.82 mm (λ∘/10). Through careful adjustment of parametric modelling, the isolation level of −23 dB among the densely packed elements is achieved. The coupling behaviour of the MIMO elements is analysed by accurately designing the equivalent circuit model in each step. The antenna performance is realized in the presence and absence of decoupling structure, and the results shows negligible effects on the antenna performance apart from mutual coupling. The simple assembly of the proposed modified U-shaped isolating structure makes it useful for several linked applications. The proposed decoupling structure is compact in nature, suppress the undesirable coupling generated by surface wave and nearby fields, and is easy to fabricate.


2018 ◽  
Vol 12 (11) ◽  
pp. 1828-1833
Author(s):  
Tien Manh Nguyen ◽  
Seung‐Ho Kim ◽  
Jin‐Young Jeong ◽  
Jong‐Hwa Kwon ◽  
Jae‐Young Chung

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yanjie Wu ◽  
Yunliang Long

This paper presents a long-term evolution (LTE) 700 MHz band multiple-input-multiple-output (MIMO) antenna, and high isolation between the two symmetrical antenna elements is obtained without introducing extra decoupling structure. Each antenna element is a combination antenna of PIFA and a meander monopole antenna. The end of the PIFA and the meander monopole antenna are, respectively, overlapped with the 50 Ω microstrip feed line, the two overlapping areas produce additional capacitance which can be considered decoupling structures to enhance the isolation for the MIMO antenna, as well as the impedance matching of the antenna elements. The MIMO antenna is etched on FR4 PCB board with dimensions of 71 × 40 × 1.6 mm3; the edge-to-edge separation of the two antenna elements is only nearly 0.037 λat 700 MHz. Both simulation and measurement results are used to confirm the MIMO antenna performance; the operating bandwidth is 698–750 MHz withS11≤−6 dB andS21≤−23 dB.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Enze Zhang ◽  
Jinghui Qiu

A four-port dual-band dual circularly polarized (CP) stack-up patch antenna is introduced for multiple-input-multiple-output (MIMO) RFID application. The proposed antenna adopts two FR 4 substrates and one Rogers Ro4350b substrates. Two pairs of isolated ports work at FCC UHF/MW-RFID bands (0.902–0.928 and 2.4–2.485 GHz) with port isolations of 20 dB and 25 dB, respectively. Four inverted-F radiating elements fed with a 90° phase-delay feeding network realize the CP radiation at the FCC UHF-RFID band (0.902–0.928 GHz). The corner-truncated square slot and patch are implemented to obtain CP modes at the MW-RFID band. The relative impedance bandwidths in the FCC UHF and MW band are 10.9% and 9.4%, respectively, with peak gains of 4.1 and 7.2 dBic. The antenna’s MIMO performance of envelope correlation coefficient (ECC) is lower than 0.01, and diversity gain (DG) is close to 10 dB. Thanks to the stack-up configuration, the dual-band RFID antenna realizes good antenna performance with a compact size of 0.6 × 0.6 × 0.07 λ3.


2017 ◽  
Vol 2017 ◽  
pp. 1-18
Author(s):  
Bernhard Auinger ◽  
Thomas Zemen ◽  
Michael Gadringer ◽  
Adam Tankielun ◽  
Christoph Gagern ◽  
...  

Over-the-air (OTA) throughput tests of wireless Multiple-Input Multiple-Output (MIMO) devices are an important tool for network operators and manufacturers. The user equipment (UE) is placed in an anechoic chamber and a random fading process is emulated by a base-station emulator (BSE). The antenna characteristic of the UE is taken into account by sampling the sphere around the UE with the BSE test antenna at a large number of positions. For low-variance throughput results, long measurement intervals over many fading realizations are required, leading to long and expensive measurement periods in an anechoic chamber. To speed up the OTA test, we analyze the Decomposition Method (DM). The DM splits the throughput measurement into two parts: (1) a receiver algorithm performance tests taking the fading process into account and (2) an antenna performance test without fading process emulation. Both results are combined into a single throughput estimate. The DM allows for a measurement time reduction of more than one order of magnitude. We provide an analytic and numerical analysis as well as measurements. Our detailed results show the validity of the DM in all practical settings.


Author(s):  
Pavithra S ◽  
AmeeliaRoseline A

In MIMO(multiple input multiple output) system, antenna performance are degraded by mutual coupling hence to overcome this we go for circular polarization. In this paper we use planar, circularly polarized MIMO patch with three grounded stubs, F-shaped mirrored structure to achieve same time isolation &matching with offset feeding between two patches for circularly polarization.The elements of antenna are closely packed with 0.06λ0 of edge to edge distance at 2.5 GHZ frequency. The proposed antenna will results the impedance matching S11 < -10 dB and high isolation of S12 < -20 dB.


2021 ◽  
Author(s):  
Faris A. Almalki ◽  
Marios C. Angelides

AbstractA recent market prediction is that 5G Fixed Wireless Access (FWA) will more than double over the next five years and trials at the same period in London suggest promising results. However, the shift to 5G FWA has raised a new set of research challenges in relation to speed of deployment and re-deployment, coverage, power consumption, end user mobility and last mile connectivity, to name just a few, because of the much higher expectations. A recent review reveals that key 5G Physical Layer technologies that will enable wide mobile and FWA have not kept up pace. In response to some of those research challenges, this paper presents the design of a 5G Multiple Input Multiple Output (MIMO) Antenna that is mounted on a tethered aerostat, and the combination of which serves as a 5G FWA aerial station. The antenna design features several novelties and the aerial station can provide last mile connectivity to a wide coverage footprint, with moderate power consumption and operating at high speeds. Both the evaluation of the antenna performance using several key performance indicators and the validation of the aerial station as a 5G FWA in a wireless sensor network (WSN) proof-of-concept application reveal efficiency gains.


Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2431
Author(s):  
Hamizan Yon ◽  
Nurul Huda Abd Rahman ◽  
Mohd Aziz Aris ◽  
Mohd Haizal Jamaluddin ◽  
Irene Kong Cheh Lin ◽  
...  

In the 5G system, multiple-input multiple-output (MIMO) antennas for both transmitting and receiving ends are required. However, the design of MIMO antennas at the 5G upper band is challenging due to the mutual coupling issues. Many techniques have been proposed to improve antenna isolation; however, some of the designs have impacts on the antenna performance, especially on the gain and bandwidth reduction, or an increase in the overall size. Thus, a design with a detailed trade-off study must be implemented. This article proposes a new C-shaped parasitic structure around a main circular radiating patch of a MIMO antenna at 16 GHz with enhanced isolation features. The proposed antenna comprises two elements with a separation of 0.32λ edge to edge between radiation parts placed in a linear configuration with an overall dimension of 15 mm × 26 mm. The C-shaped parasitic element was introduced around the main radiating antenna for better isolation. Based on the measurement results, the proposed structure significantly improved the isolation from −23.86 dB to −32.32 dB and increased the bandwidth from 1150 MHz to 1400 MHz. For validation, the envelope correlation coefficient (ECC) and the diversity gain (DG) were also measuredas 0.148 dB and 9.89 dB, respectively. Other parameters, such as the radiation pattern, the total average reflection coefficient and the mean effective gain, were also calculated to ensure the validity of the proposed structure. Based on the design work and analysis, the proposed structure was proven to improve the antenna isolation and increase the bandwidth, while maintaining the small overall dimension.


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