一种面向5G通信的宽带8单元MIMO天线设计

提出了一种面向5G的宽带8端口多输入多输出（multiple-input multiple-output,MIMO）天线.天线单元采用多枝节单极子结构,能够激发多模态,且能覆盖多频段.同时,采用弯折结构来实现小型化,且在相邻单元之间设计T形突出地结构来提高隔离度.仿真和实测结果显示,该天线在3~7.1 GHz内回波损耗大于10 dB,在3.3~7.1 GHz内隔离度高于15 dB.因为进行了有效的去耦,天线体现出明显的辐射分集特性,天线在目标sub-6 GHz频段内的包络相关系数（envelope correlation coefficient,ECC）接近0.在一8×8 MIMO系统中,计算得到的峰值遍历信道容量为43 bps/Hz,达到传统2×2 MIMO上限值的3.74倍.该8单元MIMO天线具有良好的分集和复用能力,能满足5G通信在sub-6 GHz的高速数据传输需要.     

一种应用于4G/5G频段的新型8×8频率可重构MIMO系统设计

文章提出一种可应用于4G/5G工作频段且应用分集技术解耦的8×8频率可重构MIMO系统。八天线阵列中包括4个可切换于2.6 GHz频段和3.5 GHz频段的频率可重构天线模块以及4个应用于3.5 GHz频段的5G模块。由于频率可重构技术的应用,该系统可满足网络传输速率等多种要求,进一步提高终端设备的空间利用率和系统应用的灵活性。文章给出了MIMO系统切换前后的S参数和包络相关系数等参数的计算结果,结果显示出多天线阵列的可应用性。     

一种用于WLAN/WiMAX的三频MIMO天线设计

介绍了一种用于WLAN(2.45 GHz,5.15~5.85 GHz)和WiMAX(3.50 GHz)3个频段的MIMO天线。该天线包含两个呈直角放置的E型单极子,使其产生3条耦合路径以获得3频特性。两个天线元间放置一个由接地面上凸起的T型隔离单元,降低了天线元间的耦合。仿真结果表明,该天线在其3个工作频段内的回波损耗＜-10 dB,且在工作频带内可获得15 dB的隔离度。     

基于模式抵消法的耦合环集成MIMO 天线

针对移动终端设备中MIMO 天线尺寸受限的问题,文中基于模式抵消法提出了一种耦合环结构的集成 MIMO 天线。在传统环天线结构中增加断点以调节共模频率使其与差模频率匹配,从而实现集成环天线的自解耦,无 需任何额外的解耦结构。仿真和测试结果表明,该耦合环集成MIMO 天线的-6dB 阻抗带宽为3.3~5.0GHz,隔离度 大于10 dB,天线的测试效率为52%~74%,包络相关系数(ECC)<0.15。此外,文中还进一步讨论了将该天线应用于实 际的5G 移动终端设备中。相比于已有研究,该设计具有结构简单、无需额外解耦结构、宽带等性能优势,具有较大的 工业应用前景。     

一种适用于5G智能终端的新型自解耦天线对

MIMO技术是5G通信的核心技术，然而在空间受限的智能设备上布置更多的天线将导致天线间相互耦合，造成MIMO系统性能损失；加之智能设备朝全面屏发展的趋势，天线占用的空间也被进一步压缩。因此在小的净空下实现高隔离度是当前5G智能设备天线设计的关键。针对以上问题，文中设计了一种新型自解耦MIMO天线对。该天线对的两个端口在天线一体化结构设计中考虑解耦设计，无需任何额外的解耦结构。仿真结果表明：该自解耦天线对在3.4～3.6 GHz频段上的隔离度大于19 dB;4×4 MIMO系统各端口间的隔离度在3.4～3.6 GHz频段上优于16.7 dB,ECC<0.022，系统仿真的总效率达到88%～94%；该方案在净空1 mm的前提下实现。相比于已有设计，该设计在现有5G智能手机的高集成度MIMO天线领域具有可导入性。     

一种应用于5G的紧凑型阵列天线设计

提出一种应用于5G的紧凑型阵列天线,由4个天线单元相互正交放置,通过在天线单元之间的上下两个平面分别添加4个二分之一波长的微带线,提高了天线单元间的隔离度。利用高频电磁仿真软件,对所提天线单元及阵列结构进行分析。实验结果表明,阵列天线的工作频段分别为2.72~3.92 GHz和4.74~5.42 GHz,在工作频段内各天线单元间的隔离度均低于-20 dB,完全覆盖5G所需的3.3~3.6 GHz和4.8~5.0 GHz两个工作频段。该阵列天线结构紧凑,体积仅为68.5 mm×68.5 mm×1.524 mm,能够被5G的小型化便携设备所应用。     

5G终端MIMO OTA测试与标准化研究进展

随着通信技术的发展,终端多天线系统的设计中引入了更多5G天线,MIMO技术的复杂性使得多天线用户设备在性能评估与测试验证中面临更大挑战.介绍了 5G移动终端FR1频段MIMO OTA测试技术,对比了与LTE MIMO OTA测试方法的关键差异,在实际多探头全电波暗室(MPAC)环境下采用多款5G商用终端开展了 4×4及2×2 MIMO OTA性能测试.结果表明,FR1 MIMO OTA测试方案能够有效地区分不同用户设备(UE)的多天线性能差异,且现有5G终端产品在不同测试姿态、测试角度下多天线性能差异较大.文章还从实测与标准化角度解读了 3GPP、CCSA、CTIA在5G终端FR1 MIMO OTA测试方面的研究进展.     

一种5G手机的紧凑型16单元多频MIMO天线

提出一种应用于5G智能手机中结构紧凑的16单元多频段多输入多输出(MIMO)天线阵列。该多天线系统由8个紧凑天线阵列对组成,为了预留2G/3G/4G天线的布局空间,这8个天线阵列印刷在智能手机的两侧边上。每个天线阵列对由2个紧凑的间隙耦合环路天线组成,分别布置在系统板的上、下两侧;其中上侧天线工作在LTE band 46(5 150~5 925 MHz),下侧天线覆盖LTE band 42/43(3 400~3 800 MHz)。测试结果表明该天线阵列具有良好的阻抗匹配和隔离性能。同时还对MIMO一些包络相关系数进行了研究分析。最后研究了人手和头对整个天线性能的影响,仿真结果表明,在日常各种使用情况下,该天线阵列也具有良好的辐射特性。     

一种紧凑型MIMO超宽带缝隙天线设计

设计了一种紧凑型的MIMO超宽带缝隙天线。该天线不采用任何解耦结构可以获得较高的隔离度。通过应用位置不对称的天线单元和缝隙天线来实现,这种结构可以减小天线的尺寸,设计的超宽带天线尺寸为15mm×20mm。测量结果表明,超宽带天线在3.1~12.0GHz内保持良好的全向辐射特性和稳定的增益,测量阻抗隔离比大于24dB。相关系数(ECC)和信道容量损失(CCL)都在可以接受的范围内。该天线可应用于超宽带通信系统中。     

一种小型化超宽带MIMO天线设计

提出了一种基于槽天线的小型化、高隔离度的超宽带(Ultra Wideband, UWB)多入多出(Multiple-Input Multiple-Output, MIMO)天线.该MIMO天线由两个槽天线单元构成, 为了增加天线阻抗带宽, 每个槽天线单元由末端带有圆形贴片的微带线和末端为圆形的槽线两部分耦合馈电.采用在地板上开槽和方向图分集方法, 减少地板表面波和空中电磁波影响, 达到提高天线隔离度的目的.数值仿真和实验结果表明:该天线在3.1~11 GHz频段内满足端口反射系数|S₁₁| < -10 dB, 隔离度|S₁₂|在7~11 GHz频段内小于-25 dB, 在3.1~7 GHz频段内小于-16 dB, 并根据仿真和测试S参数计算了包络相关系数.     

一种用于5G移动通信的毫米波大规模天线系统

毫米波大规模天线是目前5G研究中的热点技术之一,毫米波大规模天线可提供高增益波束和大带宽,能有效提升系统能量效率和容量.面向未来5G移动通信需求,提出一种基于数字-模拟混合波束形成架构的毫米波大规模天线设计方案.采取该方案,天线内部各单机功能界限清晰、接口明确,可极大提升天线系统的可测试性和可批量生产性.基于该设计方案...     

Broadband Multiple Input Multiple Output antenna for sub-6-GHz 5G communications

This paper presents the design of a miniaturized broadband monopole antenna for 5G and Wireless Local Area Network (WLAN) applications in mobile handsets. The proposed monopole evolved from a rectangular geometry of size 12 × 5 mm. The slot and stub loading techniques are used to improve the impedance matching offered by the antenna. Furthermore, bandwidth broadening is achieved using lumped elements loaded onto the aperture of the antenna. The proposed miniaturized antenna exhibits a measured impedance bandwidth of 63.6% (3.0–5.8 GHz) covering the 5G spectrum allocations under sub-6 GHz and the WLAN services. The antenna elements are replicated along the sides of the mock mobile handset PCB to study the functionality of the eight-element MIMO antenna. The prototype MIMO antenna fabricated and tested in the laboratory offers a peak gain of 3 dBi and total efficiency greater than 72%. Owing to miniaturization, the spatial distribution of the antenna element provides a low envelope correlation (ECC) of less than 0.2 and good diversity gain (DG) greater than 7.8 dB. In addition, the mean effective gain (MEG), channel capacity loss (CCL), multiplexing efficiency (ME), and total active reflection coefficient (TARC) are evaluated and presented. The estimated MIMO metrics are within the desired range of operation and hence make the antenna suitable for a complex propagation environment. The prototype antenna is developed on a thin microwave laminate with low-loss characteristics and tested under laboratory conditions. The outcomes indicate that the proposed eight-element antenna can be applied to 5G MIMO communications.     

Broadband sub-6 GHz flower-shaped MIMO antenna with high isolation using theory of characteristic mode analysis (TCMA) for 5G NR bands and WLAN applications

A small size neutralization line integrated flower-shaped MIMO antenna is designed and analyzed for sub-6 GHz type 5G NR frequency bands like n79 (4400–5000 MHz), n78 (3300–3800 MHz), n77 (3300–4200 MHz), and WLAN (5150–5825 MHz) applications. The novel approach of theory of characteristic mode analysis (TCMA) is introduced to provide physical insight of the designed structure and its characteristics behavior. Due to the suggested modifications in the geometry, the isolation among the patches is greatly increased. The overall miniaturized dimension of the MIMO antenna is 25 × 40 mm². The edge-edge spacing among the elements is 0.0233λ. The prototype antenna is fabricated and measured that shows good agreement compared with simulated results. The designed MIMO antenna without the presence of decoupling structure offers an isolation of 28 dB, gain of 3.6 dBi, and radiation efficiency of 69.7% at the resonant frequency. The proposed MIMO antenna covers a broad range of frequency band from 3.296 to 5.962 GHz with −10 dB impedance bandwidth of 2666 MHz and maintains a good isolation of greater than 50 dB for the entire operating band. The tested radiation efficiency and gain are 85.3% and 6.22 dBi at 3.5 GHz. Moreover, the diversity parameters of the neutralization line integrated MIMO antenna, that is, channel capacity loss (CCL) isolation, mean effective gain (MEG), total active reflection coefficient (TARC) diversity gain (DG), and envelope correlation coefficient (ECC), are analyzed and discussed in this article.     

紧凑型4×4单元超宽带MIMO缝隙天线设计

为了更好地实现移动终端天线小型化,提出了一种具有较高单元间隔离度的紧凑型超宽带（multiple input multiple output,MIMO）天线。该天线无需任何解耦网络,通过阶梯形缝隙结构来实现各个天线单元。采用的阶梯形缝隙天线不仅减少了天线的尺寸,而且具有定向辐射行为,从而形成较高的高隔离度。提出的天线尺寸为23×23mm3。测量结果表明,提出的超宽带MIMO天线在3 GHz-10.9 GHz频谱中能够产生较好的多向辐射特性（S11≤-10dB）,阻抗隔离大于20dB,包络相关系数和信道容量损耗的容许界限保证了良好的MIMO性能。     

多用途双频双极化双通道MIMO 室内基站天线

多输入多输出(Multiple Input Multiple Output,MIMO)天线是MIMO技术的关键,现代无线通信领域的迅速发展对MIMO天线提出了许多新的要求.该文利用微带天线的低剖面特性,采用双线馈电的方式实现了两款双端口的MIMO天线,其中一款基于正方形辐射贴片,两个端口都工作于2.4GHz并且具有相同的辐射特性;改变贴片的尺寸可以得到另一款双频MIMO天线,分别工作于2.4GHz和3.5GHz,可以同时覆盖LTE(Long Term Evolution)、WiMAX(Worldwide Interoperability for Microwave Access)频段与WiFi(Wireless Fidelity)的部分频段,该天线的最大增益可达8dB,并且两个端口对应两个互相垂直的极化,满足室内基站的需要.     

Compact body-worn MIMO antenna with high port isolation for UWB applications

This article investigates the mutual coupling reduction of a compact two elements wearable ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna. The ground plane of the proposed wearable MIMO antenna structure consists of three connected square ring-shaped stubs and two rectangular slots of narrow height. These ground stubs and slots minimize the mutual coupling effect between antennas and provide high isolation. The suggested MIMO antenna functions from the 1.87 to 13.82 GHz frequency spectrum covering WLAN (2.4–2.484 GHz), UWB (3.1–10.6 GHz), and X band (8–12 GHz) with 152.32% fractional bandwidth. It sustains port isolation above 27 dB throughout the 2 to 13.82 GHz frequency band. Inside the whole working frequency band, the suggested antenna offers a tiny envelope correlation coefficient (ECC < 0.098), greater diversity gain (DG > 9.93 dB), minimum channel capacity loss (CCL < 0.32 bits/s/Hz), and slight magnitude variation in mean effective gain of antenna ports (< 0.1 dB). The recommended antenna yields a SAR level below the designated threshold (<1.6 W/kg), affirming its suitability for body-worn applications. The designed MIMO antenna structure has an overall volume of 32 × 48 × 1.5 mm³.     

A miniaturized uniplanar MIMO antenna for n79/n46/millimeter-wave applications

This research suggests a compact uniplanar multiple-input multiple-output (MIMO) with four ports for n79/n46/millimeter-wave (mm-wave) applications. The size of the quad MIMO is only 30 × 30 × 0.8 mm³. MIMO system consists of four identical Z-shaped radiators and common ground on the same plane and no decoupling structures are used for isolation. The system covers the bandwidth of 1.9 GHz (4.4–6.3 GHz) with a mid-frequency of 5.6 GHz and also covers the high-band frequencies ranging from 18 to 30 GHz with a bandwidth of 12 GHz. The suggested quad MIMO is fabricated on an FR-4 board, and the measured outcomes are well in line with the simulated results. An isolation value of −11 dB has been achieved for mid-band frequency and −24 dB has been attained for mm-wave bands. Through the value of DG = 10 dB, ECC < 0.07, TARC < −3 dB, MEG < −5 dB, and the ratio of MEG = 1 dB, uniplanar quad MIMO shows acceptable MIMO diversity performance. The entire system was evaluated for the users' hand specific absorption rate (SAR) impacts and is within the limits. After the complete analysis of the miniature quad MIMO antenna, an 8-port, and a 16-port uniplanar MIMO are simulated for smartphone-sized dielectric substrates and the performances were examined. The suggested MIMO system provides an efficient single-layer MIMO antenna to 5G smartphones with high bandwidth and low SAR. The proposed quad MIMO systems are suitable for both the sub-6 GHz band and the mm-wave band.     

Design of novel compact eight-element lotus shaped UWB-MIMO antenna with triple-notch characteristics on hollow substrate

The design of novel compact two-element and eight-element lotus shaped multiple-input-multiple-output (MIMO) antenna system employing pattern diversity with enhanced isolation characteristics is presented. The proposed two-element antenna system is arranged rotationally on a square-hollow substrate resulting in an eight-element MIMO antenna system employing pattern diversity. The developed eight-element MIMO antenna system resonates in the frequency range 3.1 to 14.6 GHz housing the complete UWB band with triple band-notch characteristics at 3.7–4.5 GHz (C-band satellite down link [3.7–4.2 GHz]), 5.1–5.9 GHz (WLAN) and 6.8–8.25 GHz (X-band satellite down link (7.25–7.75 GHz) and up link (7.9–8.4 GHz)) bands. The antenna system gives element-to-element isolation of more than 25 dB in the majority of the operating band with a peak gain of 6.8 dBi and a maximum 90% efficiency. The important MIMO metrics like ECC (envelope correlation coefficient), DG (diversity gain), total active reflection coefficient (TARC), channel capacity losses (CCL) and MEG (mean effective gain) are presented for both two-element and eight-element to estimate the performance the proposed antennas in multi-antenna environments. The both two- and eight-element designs are fabricated and the measured results of those are well agreed with simulation results.