采用螺旋线实现高隔离度的车载多频宽带MIMO天线

为解决车载天线工作带宽窄和MIMO天线低频段隔离度低等问题,提出一种应用于车载通信系统的多频宽带高隔离度的MIMO天线,其工作频段为824～960 MHz和1 710～6 000 MHz,可覆盖民用移动通信的2G/3G/4G/5G和无线局域网/车联网等频段。单极子天线单元采用弯曲、开槽等诸多技术实现多频宽带,还通过添加接地枝节来降低天线高度和提高物理稳定性;在MIMO天线设计上采用螺旋线来提高天线单元之间的隔离度。实测结果表明,天线在工作频段内的反射系数小于-10 dB,隔离度小于-20 dB,低频段增益和辐射效率略低,中高频段的增益均大于4 dBi,最高达到7 dBi,效率均高于70%,最高可以达到96%。实测数据与仿真数据具有良好的一致性,所研制的天线可满足车载天线对多频段通信和高隔离度MIMO天线的技术要求,其结构和尺寸专为安装于汽车内部中控台背面而设计。     

车载鲨鱼鳍式超宽带多功能天线的研制

设计了一种用于车载应用的新型超宽带鲨鱼鳍天线。该天线工作频域覆盖了应用于车载通信的四个宽频带(824~960 MHz、 1 710~ 2 170 MHz、 2 300~ 2 690 MHz 以及3 300~ 5 000 MHz ),使得该天线系统集卫星导航、移动通信、WiFi、蓝牙、FM收音等多功能性于一体。主集天线尺寸为50 mm ×42 mm ×1.6 mm ,且由1/4椭圆单极子枝节和矩形单极子枝节组成,并将天线垂直放置在鲨鱼鳍式金属板上,从而方便了天线的制作和加工。仿真结果表明,全频段驻波比小于4 dB,全频段天线隔离度小于-15 dB ,且包络相关系数(Envelope Correlation Coefficient,ECC)小于0.1。与最大增益和辐射效率方面的实测值相比,该天线的模拟结果显示出良好的一致性,可广泛应用于车载通信系统中。     

带寄生单元宽带单极子天线研究

提出并设计了一种带寄生单元宽带单极子天线,该天线由一个单极子天线附加两个寄生振子组成.仿真及实验结果证明:天线在保持单极子天线特性的同时,实现了其宽带特性.该天线在750～2240 MHz的频带内反射损耗小于-10 dB,具有水平全向的方向图、稳定的增益.天线的结构和电特性决定了天线有广阔的应用前景,非常适用于移动通信终端设备,作为手持终端天线和车载天线将大有可为.     

一种地面开槽的双频宽频单极子天线

针对无线通信应用,设计了一种双频单极子天线,天线由共面波导馈电。天线的整体尺寸为30 mm×25 mm×0.8 mm,基板选用FR4。天线在平面单极子的基础上,通过在共面波导地平面上开槽,实现了双频特性;同时采用具有渐变结构的单极子贴片,实现了在较宽频带上良好的阻抗匹配。采用HFSS仿真软件对天线进行仿真,仿真结果表明:天线具有单极子天线的辐射特性,天线带宽较宽,在3.01~6.1 GHz反射损耗小于-10 d B,相对带宽达到了67.8%,工作频段覆盖了3.5/5.2/5.5/5.8 GHz频段。天线具有较好的全向辐射方向图和增益,其尺寸小、结构简单和易于加工,能够广泛用于WLAN和WiMAX通信系统中。     

用于平板电脑的小型化LTE/GSM/UMTS多频段天线

随着LTE在移动宽带服务中的使用,平板电脑等移动终端满足移动通信宽带化的需求日益迫切。设计了1个用于平板电脑的小型化LTE/GSM/UMTS多频段天线。天线尺寸只有15 mm×40 mm×0.8 mm。针对超薄平板电脑中平面倒置F型天线的高度要求难以实现,通过引入T型驱动单极子结构,有效降低了天线高度;通过嵌入并联谐振螺旋电感展宽了低频段(850 MHz~910 MHz)带宽;通过加载缺陷地结构展宽了高频段(1 710 MHz~2 690 MHz)带宽。天线覆盖GSM850/900/ 1800/1900/UMT2100/LTE2300/2500频段,同时天线增益也满足平板电脑的要求。     

改进的圆形单极子超宽带天线

为了有效地对圆形单极子超宽带天线进行小型化,在圆形贴片上进行切边和加圆处理,设计了一款尺寸为30 mm×31 mm的改进型圆形单极子天线。该天线印刷在相对介电常数为4.4、厚度为1.6 mm的FR4介质板上,通过改变切边圆和所加圆的尺寸对天线进行优化。实验结果表明,该天线在S11≤–10 d B的工作带宽为3.03~11.55GHz,相对带宽为116.9%。该天线减小了传统圆形单极子天线的尺寸,可应用于超宽带通信系统中。     

基于缺陷地结构的小型宽带天线设计

该文介绍了一种使用缺陷地结构的小型化超宽带天线,其尺寸为29 mm×31.5 mm×1.6 mm,该天线采用正六边形金属贴片作为天线辐射贴片。通过在介质板上引入开口谐振环,产生了新的工作谐振频段,并进一步拓宽了天线的工作频段。通过在辐射贴片上加载"十字形"分支结构,使电流路径改变,从而改善天线的宽带辐射特性。测试结果表明,该天线反射系数<-10 dB的频段为3.0～19.3 GHz。     

加载新型复合左右手传输线单元的宽带单极子天线设计

提出了一种新颖的一维复合左右手传输线(CRLH-TL)单元,并将其加载到传统微带馈电的单极子天线上,设计出一种宽带的变形单极子天线。该宽带天线工作在1.67~2.67GHz,相对带宽达到了46%,有效地覆盖了DCS(Digital Cellular System,1710~1880MHz)、PCS(Personal Communication Service,1850~1990MHz)、Wi-Fi(Wireless Fldelity,2400~2480MHz)等多个通信频段。首先,利用CRLH-TL的相位补偿效应,结合传统单极子天线的自身谐振,得到多个谐振工作频点;然后,通过参数优化,使得其中的两个工作频点相互靠近形成一个更宽的工作频段,并且在工作频段内获得了较好的增益和稳定的方向图。最后,对所设计的天线进行实物加工并测试,测试结果与仿真结果吻合良好。     

小型化准分形加载单极子天线

提出了一种小型化宽带加载单极子天线,即对有顶部加载的单极子天线进行准分形和RLC集总加载.研究表明准分形可以有效地降低天线的谐振频率,提高辐射能力.准分形加载单极子天线和三维分形树单极子天线相比,结构非常简单,容易实现,和典型的加载单极子天线相比,天线的电尺寸要小得多.对准分形加载单极子模型天线进行了测试,实测结果和仿真结果比较一致.加入匹配网络后,可得到10:1的带宽.     

一种小型化宽带双频贴片天线的设计

提出了一种基于U 形槽贴片天线设计的小型化宽带双频天线。采用基于有限元的商用软件对天线的电气特性进 行仿真和设计,制作了实验模型并进行测试,测试结果同仿真结果相吻合。结果表明,天线在824MHz~960MHz 频段和 1710MHz ~2170MHz 频段上的反射损耗均小于-10dB,相对带宽分别达到15%和24%,并且其尺寸远小于普通贴片天线。 所设计的天线可以作宽带双频天线应用于无线通信系统中。     

Cylindrical ring dielectric loaded horizontally polarized omnidirectional antenna for wideband radiation

A wideband horizontally polarized omnidirectional antenna with a cylindrical ring dielectric (CRD) loaded is proposed. Compared with the conventional alford-structure loop antenna (ASLA), the impedance and radiation pattern bandwidths are broadened by loading a CRD to the ASLA with two wing sections. The designed antenna is fabricated and measured, and good performance has been obtained. The measured reflection coefficient is less than −10 dB over the frequency band 1.63–2.8 GHz, i.e., 52.8%, which can cover 2G/3G/LTE band totally. The gain variation in all directions of horizontal plane is less than 1.4 dB in the whole band. The maximum gain is 1.56dBi throughout the operating band and it appears at 1.66 GHz. It is worth noting that the gain is around 1dBi and almost constant from 1.9 GHz to 2.7 GHz. Besides, the designed antenna has a compact size of 0.55λ × 0.55λ × 0.057λ, λ is for the lowest frequency of the operating band.     

Wideband to narrowband/dual band characteristics of monopole antenna using frequency selective surfaces

A monopole antenna having desirable transmission characteristics with high gain is proposed. The monopole antenna comprises 45° tilted square shaped patch and modified rectangular metallic ground plane on FR4 dielectric substrate. The proposed monopole antenna operates from 2.6 GHz to 9.7 GHz with maximum peak gain of 2.3 dBi. Now, a dual-layer aperture-type FSS is designed having a passband from 5.9 GHz to 9.2 GHz and incorporated with the proposed monopole antenna. Thus, the combination only covers the selective frequency band from 5.5 GHz to 8.7 GHz with a stable gain of around 5 dBi. Second, another FSS is designed, which has one stop-band from 4.1 GHz to 5.4 GHz and two passbands on the both sides of this stop-band. This combination does not work from 4.1 GHz to 5.5 GHz but covers dual band from 2.48 GHz to 3.3 GHz with a peak gain of 5 dBi and 5.5 GHz to 10 GHz with a peak gain of 5.5 dBi. Therefore, without modifying the antenna design, any tunable transmission band can be achieved by the proposed combination. The proposed antenna and FSS combination structure may be suitable for military wireless applications for its band selection characteristics.     

宽带低交叉极化超材料漏波天线的设计

基于基片集成波导结构提出了一种新型双层电磁超材料单元，并验证了其左手特性。将超材料单元应用于漏波天线的设计，所设计的天线由15个双层电磁超材料单元组成。将设计好的天线进行加工测试，测试与仿真结果吻合较好，表明漏波天线的工作频带为7.20~12.70GHz，在工作频带内可实现从后向-78°到前向+80°的连续主波束扫描，天线在工作频带内的测试增益均大于10dBi，峰值增益为15.2dBi，3dB增益带宽达到50.2%。此外，该漏波天线具有很低的交叉极化电平，交叉极化始终比主极化低至少30dB。相比于新近文献报道的同类型超材料漏波天线，所设计的天线具有更加优越的电气性能。     

Multi-band monopole antenna using meander structure for handheld terminals

A multi-band monopole antenna with wideband characteristic is proposed for DVB-H/DCS1800/PCS1900/IMT2000/Wibro/WLAN/ S-DMB applications. By using a meander structure and tapered feeding line, wideband characteristic can be achieved. The proposed antenna has an omnidirectional radiation pattern and yields greater than -4 dBi of antenna gain at the DVB-H band and 3 dBi for high- band, respectively.     

A high gain dual-band printed antenna for LTE base stations with a corner reflector

A high gain dual-band printed antenna is proposed for LTE base stations applications. The established 60 × 60 mm² broadband antenna structure is composed of two perpendicular U-shaped and L-shaped monopole antennas which are located vertically on ground plane printed on 1.6 mm thick FR4 substrate. A metallized wall is connected to the substrate which forms a corner reflector. A coaxial cable at the common center of the monopoles is adopted to excite the antenna. Wise implementation of the conductive elements and finely tuning of the monopoles dimensions yield the excitation of two resonances and dual band operation achievement. The presented antenna achieves bandwidths of 1.61–1.86 GHz and 2.25–2.45 GHz suitable for LTE applications. Stable radiation pattern, small size, cost effective fabrication, and high peak gain values of 10 dBi and 9.5 dBi at two operating bands are the prominent features of the proposed antenna topology.     

Internal antenna with modified monopole type for DVB-H applications

An internal modified monopole antenna for DVB-H band is presented. By extending the feeding line of the modified monopole and locating it over a ground plane, a wideband input impedance of 328 MHz within 6:1 VSWR is achieved. The proposed antenna has an approximately omnidirectional radiation pattern and yields greater than -3 dBi antenna gain covering DVB-H band. These features are suitable for DVB-H applications     

Compact microstrip-line-fed ring monopole antenna with tuning strip for 5 GHz WLAN operation

A novel compact and simple microstrip monopole antenna for 5 GHz wireless local area network (WLAN) operation is proposed. To excite a resonant mode in the operating band, a tuning strip is added to the antenna, which consists of a rectangular ring microstrip and a top loaded vertical strip, and is fed by a 50 /spl Omega/ microstrip line. The effects of the added strip to the impedance matching have been studied. A constructed prototype of the proposed antenna has been tested and bandwidth of about 930 MHz ranging from 5.03 to 5.96 GHz, monopole-like radiation pattern, and average gain of greater than 2.6 dBi over the operating band have been obtained.     

Multiband integrated wideband antenna for bluetooth/WLAN applications

The paper presents an O-shape multiband monopole antenna design (Antenna-I) with different patch orientations; 90-degree (Antenna-II) and 180-degree (Antenna-III). The proposed Antenna-I is a multiband integrated wideband monopole antenna with two integrated bands supporting modern wireless services such as Bluetooth and Wireless Local Area Network (WLAN) in addition to wideband covering upper Ultra-wideband (UWB) frequencies. The first band ranges from 2.05 to 3.05 GHz and second band from 3.65 to 3.92 GHz in the −10 dB impedance bandwidth range. The wideband covers upper frequencies (5.24–10.75 GHz) in the range of Ultra-wideband. Antenna-II resonates at 2.38 GHz (2.11–2.90 GHz) covering Bluetooth band and upper UWB region 5.18–10.86 GHz. The proposed Antenna-III covers 1.96–2.33 GHz and 3.74–10.46 GHz frequency bands. The antenna gain at integrated band is around 2.8 dBi and varies from 4 dBi to 8.03 dBi in the UWB region. The measured fidelity factor is 0.89 for face to face and 0.82 for side by side. Measured results are presented to validate the antenna performances.     

基于环形极子的太赫兹超宽带圆极化阵列天线

以方环单极子天线为基础,设计了一种太赫兹频段超宽带圆极化微带阵列天线。提出的新型低剖面环形天线单元由C型结构和改进后的接地结构组成,实现了天线表面电流不对称流动以及电流的最优纵横比,辐射圆极化波;采用2×4天线阵列不仅提高了天线增益,而且增强了其方向特性。仿真结果表明,该阵列天线的阻抗带宽为67.42%(193.86~391.02 GHz),圆极化轴比带宽可完全包含该频段,且在该频段内峰值增益为15 dBi,在太赫兹通信设备中具有广阔的应用前景。