A wideband high gain dielectric resonator antenna for RF energy harvesting application

A novel high gain and broadband hybrid dielectric resonator antenna (DRA) is designed and experimentally validated. To obtain the wide impedance bandwidth, the proposed antenna geometry combines the dielectric resonator antenna and an underlying slot with a narrow rectangular notch, which effectively broadens the impedance bandwidth by merging the resonances of the slot and DRA. An inverted T-shaped feed line is used to excite both antennas, simultaneously. It supports amalgamation of different resonant modes of the both, DRA and slot antenna. The measured results show that the proposed antenna offers an impedance bandwidth of 120% from 1.67 to 6.7 GHz. The antenna gain is next enhanced by a reflector placed below the antenna at an optimum distance. On engineering the height and dimension of this reflector the antenna gain is improved from 2.2 dBi to 8.7 dBi at 1.7 GHz. Finally, antenna operation is attested experimentally with a rectifier circuit in the frequency range of 1.8–3.6 GHz, where various strong radio signals are freely available for RF energy harvesting. The measured maximum efficiency of the rectifier and rectenna circuit were found to be 74.4% and 61.4%, respectively.     

Broadband,High Gain,Narrow Width Rectangular Dielectric Resonator Antenna with Air Gap

The broadband, narrow width, rectangular dielectric resonator antenna (RDRA) of aluminum nitride (ε_r=8.6) was designed and the effect of inclusion of air gap at the bottom of the dielectric resonator antenna (DRA), above the ground plane, was investigated. Gain around 7 dBi was obtained for DRA with air gap (DRAAG) over a broad bandwidth in upper X, K_u, and K bands. Further enhancement in gain could be obtained by placing a metal wall parallel to the length of DRA. However, due to the presence of metal wall, bandwidth was reduced. These structures with the metal wall are capable of operating over a wide band extending from K_u band to lower K band with the gain of around 10 dBi. CST Microwave Studio Software was used to simulate all these structures. Performance parameters of DRA with air gap were compared with several broadband DRA structures reported in recent literature. The proposed DRAAG with the metal wall in this paper is capable of operating over a wide bandwidth along with a significant gain.     

A reconfigurable wideband MIMO antenna combines RF energy harvesting

This article introduces a novel and groundbreaking approach combining multiple-input-multiple-output (MIMO) technology with radio frequency (RF) energy harvesting. The proposed antenna consists of two semi-circular monopole antenna components, optimized with dimensions of 89 × 51.02 × 1.6 mm³, that share a common ground plane to achieve MIMO characteristics. A series of split-ring resonators on the ground plane significantly enhances the isolation between the two radiating components. Band-notched features are performed in the 3.5 GHz WiMAX and 5.5 GHz WLAN bands through modified C-shaped slots in the radiating patch and two rectangular split-ring resonators serving as parasitic devices near the feed line. The reconfiguration of band-notching is made possible by controlling the modes of the embedded PIN diodes. The two antenna elements maintain mutual coupling below −18 dB from 1.5–13 GHz, achieving an impressive 158.62% impedance bandwidth. The antenna's efficiency and gain experience significant drop, indicating effective interference suppression at the center frequencies of the notch bands, and its performance in MIMO systems is assessed through parameters including envelope correlation coefficient, port isolation, radiation patterns, efficiency, gain, and diversity gain. The simulated properties of the designed antenna closely align with the measured outcomes, demonstrating its reliability and consistency. Moreover, the article evaluates the antenna's potential for RF energy harvesting, achieving a maximum harvested energy of 4.88 V. This proposed antenna can be used in multiple applications, like wideband, band-notching MIMO, and RF energy harvesting. This proposed antenna is an efficient, reconfigurable wideband MIMO antenna with novel RF energy harvesting capability.     

Statistical analysis on ambient RF energy harvesting for low‐power wireless applications

Renewable energy sources from the earth constitute another option apart from the available ones for wellspring of energy for economizing on cost of power supply. The energy obtained from ambient sources is called energy harvesting. Energy‐harvesting low‐power systems have acquired a remarkable consideration as a viable hotspot for expanding both energy efficiency and spectral efficiency. Radio frequency (RF) energy harvesting from ambient source is a promising technique for fulfilling the irreplaceable power prerequisites for powering the low‐power devices. Hence, it requires the development of an antenna for harvesting RF energy. In this paper, a coplanar waveguide (CPW) antenna has been designed and fabricated using FR4 lossy substrate. This CPW antenna covers frequency bands from the most important RF patrons (GSM 900, GSM 1800, 3G, and Wi‐Fi) within the frequency range from (0.58 to 3 GHz) with a percentage fractional bandwidth of 116% with the center frequency of 1.65 GHz. The fabricated antenna then has been experimentally validated at SSN College of Engineering campus. The effects on the RF power density level for CPW antenna are examined by statistical approach known as Taguchi method. The L9 and L8 orthogonal arrays and analysis of variance are implemented to analyze the execution qualities. The CPW antenna control factors are distance, time, and number of receivers. Then, statistical test (P) are used to determine the significant factors on RF power density.     

Dielectric Resonator Antenna on Silicon Substrate for System On-Chip Applications

This paper presents for the first time the design and performance of a novel integrated dielectric resonator antenna fabricated on a high conducting silicon substrate for system on-chip applications. A differential launcher to excite the ${rm TE}_{01delta}$ mode of the high permittivity cylindrical dielectric resonator was fabricated using the IBM SiGeHP5 process. The proposed antenna integrated on a silicon substrate of conductivity 7.41 S/m has an impedance bandwidth of 2725 MHz at 27.78 GHz, while the achieved gain and radiation efficiency are 1 dBi and 45% respectively. The design parameters were optimized employing Ansoft HFSS simulation software. Very good agreement has been observed between simulation and experimental results. The results demonstrate that integration of dielectric resonator antennas on silicon is viable, leading to the fabrication of high efficient RF circuits, ultra miniaturization of ICs and for the possible integration of active devices.      

基于零阶谐振的高增益共形全向微带天线

为了实现与飞行器的共形,通过对等效磁流模型及负介电常数零阶谐振器的研究,设计了一种零阶谐振的共面磁流环阵列天线。该天线的工作频率为5 GHz,工作于TM01模式,具有全向辐射特性,水平面增益为3.4 dB,不圆度为2 dB,半功率波瓣宽度为50°。该天线具有水平面增益高,方向图不圆度小,剖面低的特点,且易于共形。     

一种新型超宽带单极子天线设计与仿真

通过单极子和高介电常数(相对介电常数为38)陶瓷介质谐振器的耦合设计了一种新型类齿状UWB单极子天线,以实现天线超宽频带的目的。采用软件HFSS进行仿真,并对天线模型参数进行优化,得到最佳设计效果。结果表明,该天线频带宽度为2.6~20.0 GHz(S11≤–10 dB),相对带宽达到了154%,满足超宽带天线要求。该天线实现小型化超宽带的同时,在整个UWB匹配频段内,具有良好的驻波比和方向图特性,较好地兼顾了各方面的性能。     

一种宽频带介质谐振器天线的设计与实现

摘 要：带宽拓展,一直以来是介质谐振器天线研究重要内容之一。基于此,本文设计了一款宽频带介质谐振器天线。采用共面波导馈电的单极天线与介质谐振器天线的混合结构,通过调节谐振器尺寸和共面波导的结构,使各个工作模式的频带互相重叠,展宽所设计天线的带宽;同时地板上引入开槽技术,对馈线进行阻抗匹配。利用仿真软件对天线参数进行优化仿真,实现天线频带宽度为2.98-7.18GHz（S11<-10dB）,相对带宽达到84.3%,带内最大增益达到4.9dBi。对该天线进行加工测试,仿真与测试基本吻合,结果表明,该天线不仅可实现宽频带,且结构简单,尺寸小,易集成,可广泛应用于WLAN/WIMAX等通信领域。     

超宽频单极子陶瓷介质谐振器天线设计与仿真

设计了一种尺寸小、频带宽、结构简单的单板子陶瓷介质谐振器天线,该天线经由在单板子周围加一个环形的介质谐振器而成.该设计主要通过在环形谐振器中使用高介电常数的陶瓷材料降低天线的尺寸,利用环形谐振器与单板子谐振频率之间的耦合展宽天线的频带.利用仿真软件HFSS为该天线建立模型并进行优化仿真,得到了最佳的天线设计参数,优化所...     

宽带圆极化整流天线的研究与设计

针对空间微弱射频能量收集,提出了一种宽带圆极化整流天线,其主要由射频能量接收天线和多频整流电路构成.为了获得宽频带特性,接收天线的辐射贴片采用对数周期交叉偶极子.同时,两对交叉偶极子均由环形的90°相位延迟线连接,且相互正交,从而实现天线的圆极化特性.多频整流电路由两个单阶电压倍压整流电路并联而成,为了提高整流电路的性能和效率,引入了具有两个枝节的新型阻抗匹配电路.仿真结果表明:接收天线的阻抗带宽和3 dB轴比带宽分别为1 100 MHz和350 MHz;多频整流电路的功率灵敏度达到-35 dBm,最大RF-DC整体转换效率可达76.5%.在辐射强度为6.02 μT,负载电阻为700 Ω时,测得整流天线负载端的输出电压约为139 mV,因此该整流天线适用于低功率射频能量收集应用.     

Novel miniaturized folded UWB microstrip antenna‐based metamaterial for RF energy harvesting

This paper presents a design of an ultra‐wideband (UWB) cylindrical metamaterial (MTM) antenna for radio frequency (RF) energy harvesting to suit the fields of Internet of Things (IoT) applications. The patch circuitry is based on 3×5 Hilbert‐shaped MTM unit cells array to enhance the antenna bandwidth. While, the antenna ground plane is defected with an electromagnetic band gap structure to enhance the gain. The antenna is mounted on a polytetrafluoroethylene cylindrical substrate of an outer diameter of 15 mm and length of 32 mm with 1 mm in thickness. The substrate relative permittivity is 2.04, and the loss tangent is 0.0002. The antenna patch and the ground plane structures are printed with silver nanoparticles ink using a ^2.5D CNC plotter machine. The fabricated prototype provides an UWB over the frequency range from 3.77 up to 13.89 GHz with a first separate resonant mode at 3 GHz. The antenna performance is tested numerically using two different software packages of CST MWS and HFSS. Then, an experimental validation is conducted to realize the performance of the proposed antenna in harvesting the RF energy. Excellent conversion efficiency, about 90%, is achieved at 5.8 GHz. Finally, the antenna radiation patterns and S₁₁ spectrum are measured and compared against their simulated results to achieve good agreements.     

星载DBF多波束发射有源阵列天线

 低轨通信卫星大容量、终端小型化要求卫星采用多波束天线技术来实现高增益、宽覆盖.本文针对低轨CDMA通信系统,设计了具有近"等通量"覆盖的平面阵列多波束发射天线,该天线由61微带单元天线阵、61个发射射频通道和数字波束形成网络组成;数字波束成形网络对输入的16个波束信号进行正交化、加权处理输出61路中频信号,由发射射频通道完成上变频和信号放大,最后通过天线阵辐射出去在空间形成期望的16个赋形波束覆盖.文章详细介绍了天线的实现方法和试验结果,通过对16波束发射天线原理样机的测试,结果表明天线各指标都符合设计要求,有效验证了天线系统设计的正确性.     

Rigorous Analysis of Rectangular Dielectric Resonator Antenna With a Finite Ground Plane

A probe-fed rectangular dielectric resonator antenna (RDRA) placed on a finite ground plane is numerically investigated using method of moments (MoM). The whole structure of the antenna is exactly modeled in our simulation. The feed probe, coaxial cable and ground plane are modeled as surface electric currents, while the dielectric resonator (DR) and the internal dielectric of coaxial cable is modeled as volume polarization currents. Each of the objects is treated as a set of combined field integral equations. The associated couplings are then formulated with sets of integral equations. The coupled integral equations are solved using MoM in spatial domain. The effects of ground plane size, air gap between dielectric resonator and ground plane, probe length, and position on the radiation performance of the antenna including resonant frequency, input impedance, radiation patterns, and bandwidth are investigated. The results obtained for the antenna parameters based on the MoM investigation shows that there is a close agreement with those obtained by measurement. Moreover it is shown that the MoM results are more accurate than other simulation results using software package such as High Frequency Structure Simulator (HFSS).      

Energy efficiency of massive MIMO wireless communication systems with antenna selection

Massive multiple-input multiple-output (MIMO) requires a large number (tens or hundreds) of base station antennas serving for much smaller number of terminals, with large gains in energy efficiency and spectral efficiency compared with traditional MIMO technology. Large scale antennas mean large scale radio frequency (RF) chains. Considering the plenty of power consumption and high cost of RF chains, antenna selection is necessary for Massive MIMO wireless communication systems in both transmitting end and receiving end. An energy efficient antenna selection algorithm based on convex optimization was proposed for Massive MIMO wireless communication systems. On the condition that the channel capacity of the cell is larger than a certain threshold, the number of transmit antenna, the subset of transmit antenna and servable mobile terminals (MTs) were jointly optimized to maximize energy efficiency. The joint optimization problem was proved in detail. The proposed algorithm is verified by analysis and numerical simulations. Good performance gain of energy efficiency is obtained comparing with no antenna selection.     

Dual band dielectric resonator antenna for wireless application

The proposed technique is an integration of a slot antenna and a dielectric resonator antenna (DRA). This is designed without compromising miniaturisation and efficiency. It is observed that the integration of slot and dielectric structure itself may be merged to achieve extremely wide bandwidth over which the antenna polarisation and radiation pattern are preserved. Here the effect of slot size on the radiation performance of the DRA is studied. The antenna structure is simulated using the CST software. The simulated results are presented and compared with the measured result. This DRA has a gain of 7.1 and 6.3?dBi at 5.7 and 8.1?GHz, respectively, its 10?dB return impedance bandwidth of nearly 4.5% and 5.5% at two resonating frequencies. A total of 98% efficiency has been achieved from the configuration. It is shown that the size of the slot can significantly affect the radiation properties of the DRA and there are good agreements between simulation and measured results.     

超宽带单极子加载介质谐振器天线的设计

该文设计了一种尺寸小,频带宽,结构简单的单极子陶瓷介质谐振器天线。在单极子天线周围加载一个环形的陶瓷介质谐振器,利用环形谐振器与单极子谐振频率之间耦合来展宽频带。利用仿真软件HFSS建立天线的模型,并对模型进行优化仿真,得到了最佳的天线设计参数,仿真得到的天线频带宽度为0.7～4.6GHz,相对带宽达到了153%,使用矢量网络分析仪对该天线进行测量,实测结果与仿真值基本吻合。     

Combination dielectric resonator, power combiner, and antenna

A rectangular dielectric resonator housed in a cutoff parallel-plate waveguide is used both as a radiating element and microwave power combiner. The resonator is excited by using tuned electrically short monopole antennas to induce a longitudinal electric operating mode. The resonator is then used in conjunction with free-running oscillators in order to provide, via mutual injection locking, stable in-phase power combining. Furthermore, the resonator is arranged such that one of its faces radiates a portion of the power-combined signal. Since the resonator is housed in a cutoff waveguide, the cross-polarization radiation from the antenna is suppressed. It was found that, for a single element, a gain in the azimuthal plane of 5 dB could be achieved and, for a two-element array, a gain of 7 dB was obtained with better than -25-dB cross polarization for each case. The oscillator power-combining efficiency for a single-element antenna (two oscillators) was 91%, and the spatial power-combining efficiency for a two-element antenna array, (four oscillators) was found to be 90%. In addition, it is shown that the presence of the dielectric inserts in conjunction with coupled oscillator dynamics provides moderate overall oscillator phase noise improvement     

基于零折射超材料的双频高增益微带天线*

基于双面对称单环开口谐振器对结构奇异的电磁特性,设计了一种频率可控的各向异性零折射超材料。将这种零折射超材料应用于普通双频微带天线,制备了中心频率为5. 15GHz 和6. 8GHz 的零折射双频微带天线。仿真和测试结果显示,由于零折射超材料的引入,天线的侧向辐射减弱,方向性增强。在低频工作时,零折射微带天线E 面和H 面半功率波束宽度分别减小了29°和10°,增益提高了2. 2 dB。在高频工作时,零折射微带天线E面和H 面半功率波束宽度均减小了16毅,增益提高了2. 4 dB。将零折射超材料应用于微带天线的介质基板,为高性能双频微带天线设计提供了有效途径。     

介质加盖高增益微带天线的优化

本文提出了利用点源增益优化方法设计介质加盖的高增益微带天线的方法,所确定的各介质层的电厚度能保证天线取得最高的增益。同时优化计算量也成倍减少。所设计的一个两层介质加盖微带天线的最高增益达到16.8dB。分析结果还表明,在一定条件下,增益和效率是可以兼顾的,用加盖的方法提高天线增益的同时仍可使天线具有较高的辐射效率。     

Bandwidth Enhancement of Circularly Polarized Dielectric Resonator Antenna

Axial‐ratio (AR) bandwidth enhancement is achieved for a circularly polarized (CP) cylindrical dielectric resonator antenna (DRA) using a wideband hybrid coupler (WHC) combined with dual probe feed. The presented WHC, comprised of a Wilkinson power divider and a wideband 90° shifter, delivers good characteristics in terms of 3 dB power splitting and consistent 90° (±5°) phase shifting over a wide bandwidth. In turn, the proposed CP DRA, for the employment of the WHC, in place of conventional designs, provides a significant enhancement on AR bandwidth and impedance matching. The antenna prototype with the WHC exhibits a 3 dB AR bandwidth of 48.66%, an impedance bandwidth of 52.5% for voltage standing wave ratio (VSWR) ≤ 2, and a bandwidth of 44.66% for a gain of no less than 3 dBi. Experiments demonstrate that the proposed WHC is suitable for broadband CP DRA design.