一种基于开关控制的小型化频率可重构倒F天线

本文提出了一种基于开关控制的小型化频率可重构IFA,能够利用布置在天线和共面波导(CPW)馈电的折叠槽内的多处开关实现IFA在不同频段上的谐振。本文所设计的IFA适用于2.5GHz和3.5GHz两个频段,利用开关选择不同的IFA分支来实现对应两个频段的切换。该设计通过改变CPW馈电结构上折叠槽的相对位置和长度能够改变天线的谐振频率,利用开关进行多条折叠槽的选择以及折叠槽长度的选择来实现频率可重构的目的。仿真结果表明,该设计可以实现在2.57GHz至3.58GHz频段内的频率可重构。     

一种基于AFSS的可重构天线设计

针对5G智能天线双频工作,提出一种基于有源频率选择表面（active frequency selective surface, AFSS）的可重构天线,该天线由蝶形频率可重构馈源和八棱柱形AFSS构成,馈源采用的是共面波导方式馈电的蝶形单极子. AFSS由对称弯钩状缝隙的周期结构构成,通过PIN二极管进行加载,使得AFSS能够在3.4～3.6 GHz和4.8～5.0 GHz两个5G频段互为反射模式和透射模式. 利用AFSS对馈源天线激励的电磁波进行空间调控,可实现两个频段的全向和定向波束的切换,也可实现水平面波束扫描. 根据仿真设计的天线模型进行设计加工和实际测试,结果表明:该天线的工作频段可以覆盖以上两个频段,低频定向波束增益为7.6 dBi,高频定向波束增益为8.6 dBi;并且能实现高/低频双波段切换、全向/定向波束切换和水平面内360°波束扫描功能. 该天线具有波束切换灵活、功耗低、造价低等特点,在新一代无线通信系统中具有一定的应用价值.     

一种新型的具有陷波功能的超宽带天线仿真与设计

提出了一种新型的具有陷波功能的共面波导(CPW)馈电的超宽带(UWB)天线,基于有限元电磁仿真软件HFSS对天线结构参数进行大量仿真优化,最终天线阻抗带宽为2.SGHz～ 12.0GHz,在3.3GHz～3.8GHz频段范围内实现了陷波阻带,在带通频段范围内实现了良好的辐射特性,并且具有较稳定的增益,为2.7dBi～5.8dBi.     

一种具有三阻带特性的超宽带天线的设计与研究*

提出了一种紧凑型共面波导馈电的具有三阻带特性的超宽带天线。所设计天线的基本几何结构由共面波导(CPW)馈电线、菱形辐射贴片和矩形宽缝隙组成。通过在辐射贴片上刻蚀一个U型槽,以及在共面波导的接地面上增加两对L型的寄生旁枝结构来实现天线的三陷波特性。天线尺寸为32mm×32mm×0.508mm。仿真和实验结果表明,该天线在2.6~11.5GHz的频段内电压驻波比小于2,在3.15~3.80GHz、5.20~5.80GHz和8.2~8.7GHz三个频段内具有陷波特性,分别有效阻隔了Wi MAX系统、WLAN系统和ITU 8GHz频段信号对于超宽带(UWB)系统的干扰。在除三个阻带频段外的其余UWB工作频段范围内,具有良好的辐射方向特性和稳定的增益。仿真结果和实验结果表现出良好的一致性。     

差分馈电双极化四波束方向图可重构天线

提出了一种平面差分馈电双极化四波束方向图可重构天线. 该天线由两个相互正交的偶极子和四个带PIN二极管的寄生单元构成,有两个差分馈电端口,通过短截微带线给两个相互正交的偶极子馈电. 两个偶极子正交摆放、异面垂直,与寄生单元蚀刻在同一基板上,整体结构简单. 切换PIN二极管的不同状态得到四个波束的方向图可重构和两种方式的极化可重构. 实验表明,?10 dB阻抗带宽为8.9%,覆盖3.27～3.58 GHz频段,平均增益为5.6 dBi,前后比约为10 dB,平均辐射效率为68%. 该天线结构紧凑、成本低、易加工.     

用于生物医疗的共面波导馈电双频植入式天线

设计了一款用于生物医疗的微小紧凑型共面波导馈电双频植入式天线。该天线工作于工业、科学和医疗(Industrial Scientific Medical, ISM)低频段(433~434.8 MHz)及无线医疗遥测服务(Wireless Medical Telemetry Service, WMTS)频段(1.395~1.40 GHz),尺寸仅为10 mm×10 mm×1.27 mm。天线采用共面波导馈电结构,易于和其它结构集成,采用高介电常数介质基板和折合蜿蜒类偶极子结构使天线尺寸得以有效缩小。在满足SAR(Specific Absorption Rate,比吸收率)值标准的前提下,采用U形接地板,以获得较高的增益,在两个频段内谐振频率处的最高增益分别为-32.23 dBi和-20.63 dBi,提升了天线性能。最后,基于仿真结果制作天线实物并进行了测试,实测数据与仿真结果吻合较好。研究成果可为植入式天线研制与应用提供重要参考。     

几种共面波导耦合馈电装置的特性研究

该文研究了4种共面波导耦合缝对单贴片微带天线的谐振频率以及带宽的影响,并利用天线近场分布对其进行解释;分析并比较了几种耦合缝的馈电特性,极大地提高了天线设计的灵活性;运用变频思想对馈电装置进行改进设计出了一阻抗带宽达28.9%的宽频带天线,在3.76～4.80GHz的工作频段内天线增益均大于8dBi,增益带宽达24.2%。     

一种四频段多L型缝隙天线研究与设计

设计了一款共面波导馈电的多L型缝隙天线.通过在一个三角形辐射贴片上开L形缝隙实现多频的性能, 优化调整L形缝隙的大小以及相关参数可以灵活控制其每个频段的带宽.该天线具有多频带、小型化等特性, 通过共面波导馈电和采用高介电常数基板的方法降低了天线的谐振频率, 使得天线可以工作在更低频段.通过电磁仿真软件HFSS13.0对天线性能进行大量仿真实验与计算, 该天线在回波损耗小于-10 dB以下时, 其工作频段为1.254~1.276 GHz、1.537~1.623 GHz、1.804~1.845 GHz、2.097~3 GHz.该天线的结构简单、易于加工实现, 能够满足GPS、第三代第四代移动终端内置天线的小型化和多频段的要求.     

卫星导航终端的小型化方形四臂缝隙螺旋天线

设计了一种卫星导航终端的小型化四臂缝隙螺旋天线。天线为方形柱状结构,四条缝隙螺旋臂印制在介质基板外表面,馈电网络印制于介质基板内表面进行耦合馈电;馈电网络为弯折的微带线结构,并延伸至天线底部实现同轴馈电。天线尺寸为23.6 mm×23.6 mm×53.0 mm,实测结果表明,|S11 |≤-10 dB 的阻抗带宽为7.63%(1.512~1.632 GHz),轴比≤3 dB 的圆极化带宽为3.35% (1.556~1.609 GHz),在北斗B1频段中心频率(1.561 GHz)和GPS L1 频段中心频率(1.575 GHz)处增益分别达到4.31 dBi 和4.84 dBi。该天线采用缝隙螺旋结构,并通过简易的馈电网络耦合馈电实现螺旋天线的圆极化,结构小巧简单,适合批量生产,可应用于卫星导航系统终端设备。     

应用于WiFi/WiMAX的三频超介质加载天线

以研究超介质结构在天线中的应用为目的,采用了超介质理论中的负折射率传输线(NRI-TL)加载技术,设计了一种三工作频段的单极子贴片天线.该单极子天线由不均匀弯折线构成,采用共面波导(CPW)馈电.在2.45 GHz和55 GHz附近弯折线与超介质结构可形成折合单极子辐射;在3.55 GHz附近超介质结构可改变天线表面电...     

Dual-band CPW-fed folded-slot monopole antenna for RFID application

A folded slot with open end is introduced to achieve a dual-band coplanar waveguide (CPW)-fed monopole antenna for radio frequency identification (RFID) applications. The designed antenna, which, including the substrate, is only 32 mm in height and 20 mm in width, can operate simultaneously at the 2.45 and 5.8 GHz bands with -1.8 and 2.3 dBi gains, respectively. Its properties make the antenna suitable for RFID tags     

基于S-PIN二极管的频率可重构缝隙芯片天线研究

为了实现高度集成化的片上可重构天线系统,利用硅基固态等离子体表面PIN(S-PIN)二极管技术,设计了一种C—Ku波段频率可重构的领结型缝隙芯片天线。文中讨论了利用S-PIN二极管作为芯片天线频率可重构部件的设计标准,并对S-PIN二极管的结构参数进行了分析。通过控制S-PIN二极管的截止/导通状态,提出的缝隙芯片天线可以实现从6.7 GHz到17.97 GHz的工作频率可重构,增益分别为4.63 dBi和3.4 dBi。在实际的流片和测试过程中发现,文中研制的S-PIN二极管具有良好的伏安特性。此外,固态等离子体天线工作在C波段和Ku波段时的实际中心工作频点分别位于6.6 GHz和17.9 GHz,与仿真结果相比具有良好的一致性,验证了S-PIN二极管在制造频率可重构芯片天线方面的潜力。     

Bandwidth and frequency agile MIMO antenna for cognitive vehicular communications

A reconfigurable MIMO antenna for heterogeneous vehicular networks is reported in this paper. The frequency and bandwidth characteristics of the MIMO antenna can be reconfigured to meet multi-standard and multi-frequency requirements in automobiles. The antenna element evolved from an edge-chamfered ultra-wideband (UWB) antenna operating from 2.1 to >15 GHz. The bandwidth reconfiguration is achieved through the selection of excitation paths connecting the feed and radiator. The feedline selection is performed using PIN diodes, making the antenna operate in three distinct modes, namely, UWB mode (Mode 1: 2.1–>15 GHz), industrial, scientific and medical/Internet of Things (ISM/IoT) mode (Mode 2: 2.45 GHz), and wireless local area network (WLAN) mode (Mode 3: 5–6 GHz). The feed path corresponding to Mode 2 and Mode 3 is incorporated with a suitable filtering network to shape the frequency response of the antenna based on the user's requirements. Owing to the requirement of cognitive selection of frequency bands, the frequency tunability in Mode 2 is realized using varactor diodes. The varactor-incorporated feed path reconfigures the center frequency between 2.45 and 3.5 GHz. The proposed MIMO antenna offers gain and total efficiency greater than 2.94 dBi and 76%, respectively. The prototype of the 4-port MIMO antenna is being fabricated to test its functionality in real time.     

Dual-band polarization and frequency reconfigurable antenna using double layer metasurface

In this paper, a polarization and frequency reconfigurable antenna with double layer metasurface, responsible for frequency and polarization reconfiguration respectively, is proposed. This antenna could operate in linear polarization in 4 GHz and circular polarization in 5 GHz band. By rotating the frequency reconfiguration metasurface, the linear polarization (LP) operating frequency can be continuously changed from 4 GHz to 4.35 GHz (8.4%) with circular polarization operating frequency around 5 GHz unchanged. Moreover, polarization of the whole antenna at 5 GHz can be reconfigured to linear polarization (LP), right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP) by rotating polarization reconfiguration metasurface, the 3 dB axial ratio bandwidth is 5.0–5.2 GHz (4%). In all states, gain of the antenna achieves 5 dBi.     

一种小型化双陷波可重构UWB天线设计

提出了一种小型化的双陷波可重构超宽带(ultra wide band, UWB)天线,通过在辐射贴片上刻蚀大、小两个C形槽,实现5G (3.3~4.4 GHz)/WiMAX (3.3~3.6 GHz)和WLAN (5.150~5.825 GHz)两个频段的陷波. 采用两个PIN二极管跨接在C形槽上,通过控制PIN二极管的通断状态,在两个频段上实现陷波可重构. 为了实现小型化,天线采用削顶圆形结构的辐射贴片,并将C形槽设计为嵌套结构,天线最终尺寸为18.0 mm×19.5 mm. 仿真与测量结果表明:天线可以在UWB、两种单陷波和双陷波共四种状态下工作,UWB频段为3.1~11.0 GHz,两个单陷波频段分别为3.2~4.9 GHz、5.2~6.0 GHz,双陷波频段为3.25~4.75 GHz和5.3~6.1 GHz. 天线的最大增益为2.8 dBi,具有良好的辐射特性.     

Design of Dual‐Band MIMO Antenna with High Isolation for WLAN Mobile Terminal

In this paper, we propose a dual‐band multiple‐input multiple‐output (MIMO) antenna with high isolation for WLAN applications (2.45 GHz and 5.2 GHz). The proposed antenna is composed of a mobile communication terminal board, eight radiators, a coaxial feed line, and slots for isolation. The measured ?10 dB impedance bandwidths are 10.1% (2.35 GHz to 2.6 GHz) and 3.85% (5.1 GHz to 5.3 GHz) at each frequency band. The proposed four‐element MIMO antenna has an isolation of better than 35 dB at 2.45 GHz and 45 dB at 5.2 GHz between each element. The antenna gain is 3.2 dBi at 2.45 GHz and 4.2 dBi at 5.2 GHz.     

Compact triple-band slotted monopole antenna with asymmetrical CPW grounds

By embedding slots into a rectangular patch a triple-band slotted monopole antenna fed by a coplanar waveguide (CPW) with two asymmetrical ground planes can be obtained. The designed antenna, which, including the ground plane, is only 9/spl times/20 mm/sup 2/, can excite resonant modes at 2.43, 5.23 and 7.14 GHz bands with measured impedance bandwidths of 14.4, 8.2 and 16.7%, and average antenna gains of /spl ges/2.4, 4.7 and 6.7 dBi, respectively. The antenna is very compact and suitable for 2.4/5.2 GHz WLAN operations.     

Compact CPW-fed dual-band antenna

A novel coplanar waveguide (CPW) antenna is proposed for dual-band WLAN applications. It comprises a rectangular patch, a rectangular notch cut at the lower edge of the patch and a CPW transmission line. The rectangular patch together with the ground plane of the coplanar waveguide radiates at the lower frequency band, 2.4 GHz for IEEE 802.11b/g, while the rectangular notch resonates in the upper band, 5.2/5.8 GHz for IEEE 802.11a. The designed antenna is only 32 × 5 mm, which can provide stable omnidirectional radiation patterns with an average gain of 2 dBi in both the bands. The antenna is very compact and suitable for 2.4 and 5.2/5.8 GHz WLAN operations.