基于左右手传输线的小型天线设计

基于复合左右手传输线技术研究设计超小型的天线,通过对复合左右手传输线结构的适当调整获得一个零阶谐振天线,此时天线的工作频率不再依赖于天线的几何尺寸,而只与构成左手传输线的电感与电容相关,从而可大大降低天线的几何尺寸。文中基于复合左右手传输线设计了一款小型天线,使其可以工作在ISM频段,能够满足无线局域网(2.4~2.4835GHz)的要求。     

Coplanar waveguide-fed slot-loop antenna with left-handed loading

基于复合右左手传输线的非线性相移特性,提出了一种左手加载的共面波导激励槽环天线.该天线由四个简化的复合左右手传输线结构单元构成,通过调整单元的并联电感值,可以改变天线的谐振频率和输入阻抗,利用仿真方法分析了天线的性能.结果表明,相比于传统天线,新天线尺寸减小了30.25％,总辐射效率达到98.34％,同时交叉极化比提高了2.9 dB.     

基于左手材料的天线小型化技术研究

分析了左手材料实现小型化天线的理论依据,分析、设计了一种基于蘑菇型复合左右手传输线的微带天线,工作在1.6 GHz,并利用电磁仿真软件进行了优化,给出了利用复合左右手传输线结构的后向波效应,该天线不仅结构简单而且天线尺寸在X轴方向缩减了40.3％,在Y轴方向缩减了52.7％.     

新型左手传输线馈电微带阵列天线

提出了一种采用复合左右手传输线馈电的新型微带阵列天线.该天线利用左手传输线的相位超前特性来补偿传统的右手传输线所具有的相位滞后,从而保证了天线单元之间的同相位馈电,避免了因相位延迟导致的天线波束偏移,并进一步提高了天线的增益.仿真与实际测试证明:与同类型天线相比,该天线具有尺寸小、频带宽和馈电网络设计简单等优点,可在微波系统中实际使用.     

基于左手传输线的双线极化微带阵列天线

基于左手传输线,提出了一种新型串联馈电的双线极化微带阵列天线结构.通过上层微带线边馈和下层小孔耦合馈电的方式分别实现了天线单元的垂直极化和水平极化的激励,进而使得该天线单元具有高极化隔离度、低交叉极化和宽频带工作等优点.同时由于左手材料具有相位超前的特性,利用传统的右手微带传输线和左手微带传输线的组合以达到零相位延迟,实现了对上述单元构成的微带阵列天线的串联馈电.相对于传统微带阵列天线,该阵列天线结构简单、面积小、插入损耗小、阵列效率高、易于扩展成更大的平面阵列.     

一种频带展宽的小型化左手偶极子天线的设计

左手传输线加载偶极子(简称左手偶极子)可以有效实现天线的小型化,但是这种天线通常带宽窄、效率低。通过采用一种渐变的梯形网络结构代替传统的非渐变的结构形式来改善天线的阻抗特性,设计了四单元的左手偶极子天线,进而拓展了天线的带宽,天线总长度为0.2。仿真和实物测试结果显示:天线同时工作在–1阶和–3阶谐振模式,|S11|≤–10 dB的阻抗带宽达到6.5%,在工作频段内(571~610 MHz),天线的增益不小于–4.25 dBi,效率大于25%。     

基于复合左右手传输线的圆极化天线

根据复合左右手传输线(CRLH-TL)基本原理,设计了一种带有CRLH-TL结构的圆极化天线。通过双螺旋槽结构和底部的矩形金属条来引入左手模式,利用割除正面辐射贴片上的两个矩形的方法,产生圆极化辐射。设计并制作的微带天线整体尺寸为50 mm×40 mm×16 mm,天线的实测阻抗带宽(<-10 dB)为32.4%(2.38～3.30 GHz),实测轴比带宽(<3 dB)为6.90%(2.66～2.85 GHz),并在该工作频段下实现了相对磁导率和相对介电常数双负的左手模式特性。     

基于CRLH-TL的直线天线阵性能分析与仿真

提出利用左手材料的相位超前特性作为相位补偿器,调整传输线相位分布,并与右手材料相结合构成左右手传输线,用于为直线天线阵馈电,实现不同的天线馈电条件,达到不同的天线辐射特性.分析了无耗级联左右手传输线模型的相位特性,建立了基于左右手传输线的直线天线阵模型,对天线阵方向特性进行了仿真.结果表明,文中设计的天线性能明显优于传统直线天线阵.     

谐振-传输线复合结构左手材料设计

提出了一种谐振-传输线复合结构左手材料单元.该结构基于谐振型左手材料、复合左右手传输线理论设计,可在不同排列方式下产生多种左手特性.基于曙光云计算服务平台,分析了该材料单元结构的谐振特性、单元阵列的传输线特性,并进一步对其谐振特性中的负折射特性进行了仿真验证.实验表明:单一结构单元条件下,该结构可体现出由谐振特性产生的左手频带;在阵列条件下,可同时体现出左右手传输线特性以及谐振型左手特性.该结构的多种左手特性,或可在5.8 GHz频率范围内民用级微波器件领域获得广泛应用.     

左手微带传输线在毫米波天线阵中的应用

提出了一种新的左手微带传输线结构．基于这种结构,构建了左-右手混合式天线阵微带馈线,通过控制该馈线中主、右手传输线的长度,可以在特定长度传输线上获得零相位延迟．将此种传输线作为馈线应用到串联馈电的毫米波微带天线阵中．结果表明,利用此种传输线馈电和传统右手传输线馈电相比,可以避免由传统右手馈线在天线激动点之间引入的相位差,从而克服了固有的天线波束偏移．     

Small-size CPW silicon resonating antenna based on transmission-line meta-material approach

A small-size zeroth-order resonating antenna based on a composite right/left-handed transmission line (CRLH TL) fabricated on high resistivity silicon substrate using coplanar waveguides (CPW) is proposed. The CRLH TL consists of a series of CPW interdigital capacitors and parallel short-ended CPWs. The predicted and experimental results for return loss, gain and radiation pattern are in very good agreement.     

频带展宽的复合左右手传输线偶极子天线

针对周期复合左/右手(Composite Right/Left-Handed, CRLH)传输线偶极子天线带宽窄的问题, 提出一种非周期CRLH传输线的天线模型.该模型主要由N个不同尺寸的LC梯形网络单元组成, 实现参差调谐, 改善天线的阻抗匹配, 拓展天线带宽.设计了一种四单元非周期CRLH偶极子天线, 模拟和实验测试结果表明:天线的长度为0.135λ₀时, 满足回波损耗|S₁₁|≤-10 dB的相对阻抗带宽为8.55%, 天线的匹配性能得到了改善.     

Novel design of tri-band bandpass filter based on fractal-shaped geometry of a complementary single split ring resonator

A novel electrically small composite right/left-handed transmission line (CRLH TL) cell based on the Minkowski-shaped geometry of a complementary single split ring resonator is proposed and analysed by the S parameters extraction method. EM simulation results have confirmed the roughly tri-band response of the proposed CRLH TL cell attributed to the fractal multiband nature. A tri-band bandpass filter (BPF) centred at 1.1, 2 and 2.74?GHz with minimum insertion loss 0.4, 1.1 and 1.45?dB was synthesised and fabricated by employing an additional two Hilbert-shaped quarter-wave open-circuit stubs which provided transmission zeros located between passbands to obtain high selectivity. This simple design concept was verified by measurement as well as simulation results.     

基于左右手复合传输线的威尔金森功分器

基于左右手复合传输线(CRLH TL),提出了一种新型并行馈电的Wilkinson功率分配器.采用奇偶模分析方法证明了在Wilkinson功分器中用左右手复合传输线替代传统传输线的可行性,有效减小了功分器的尺寸.同时利用左右手复合传输线较平滑的相频特性,拓宽了新型左右手复合传输线功分器带宽.实测结果表明:和传统Wilkinson功分器相比,左右手复合传榆线功分器带宽能大幅度提高带宽,减小器件面积.另外与串行馈电CRLH功分器相比,由于左右手复合传输线Wilkinson功分器结构对称,各输出端口具有很好的相位一致性,隔离电阻的存在,使其各端口间也拥有较好的隔离度.     

Composite Right/Left-Handed Transmission Line With Wire Bonded Interdigital Capacitor

An enhanced composite right/left-handed (CRLH) transmission line (TL) is presented in this letter. This TL, designed in microstrip technology, is implemented by means of a new improved interdigital capacitor (IDC), the so-called wire bonded IDC (WBIDC). The use of the WBIDC broadens the frequency band where the CRLH TL can be considered as a TL. A conventional 70-Omega CRLH TL (using IDCs) has been compared, by full-wave simulation and measurements, with its enhanced counterpart (using WBIDCs). In addition, this enhanced CRLH TL has been used to design a CRLH diplexer which presents several advantages over standard CRLH coupled lines (using IDCs). The diplexer response has been verified by means of a full-wave electromagnetic solver     

左手材料在线极化微带贴片天线上的应用

为了实现提高天微带天线增益,减小天线波瓣宽度的目的,利用左手材料的零折射率特性,对线极化微带天线进行了增加覆盖层的处理.对由色散稳定的左手介质结构单元用组成的覆盖层进行了结构仿真优化.测量结果表明使用左手材料覆盖层后天线波瓣减小了8°,增益提高了1.8 dB.     

Characteristics of the composite right/left-handed transmission lines

The composite right/left-handed (CRLH) transmission line (TL) is presented as a general TL possessing both left-handed (LH) and right-handed (RH) natures. The dispersion diagram of the two-dimensional (2-D) CRLH-TL is obtained analytically based on the Bloch-Floquet theory, and the unique phenomenon of infinite guided-wavelength propagation, with nonzero group velocity at a nonzero frequency, is explained. It is shown analytically that when the CRLH TL is "balanced", two eigenfrequencies at the /spl Gamma/ point (/spl beta/=0) of the Brillouin zone (BZ) degenerate at /spl omega//sub /spl Gamma// and a seamless transition from the LH to the RH modes without a bandgap can be achieved. In addition, these phenomena are demonstrated experimentally in the case of a CRLH microstrip line.     

基于CRLH TL的小型化宽频带手机天线设计

主要阐述基于复合左右手传输线(CRLH TL)零阶谐振模设计小型化宽频带的手机天线。该天线低频段由尺寸较大的零阶谐振天线决定,高频段由尺寸较小的零阶谐振天线决定,尺寸较大的零阶谐振天线的右手模式与尺寸较小的零阶谐振天线的零阶谐振模谐振在相邻的频带上实现频带融合,从而扩展高频段的带宽。该天线覆盖了GSM900、PCS、UMTS、Bluetooth和ISM2400五个移动通信频带,天线厚度仅为1mm,所占面积为37×15mm2。测试结果与仿真结果吻合,满足移动通信终端对手机天线的要求。     

Wide-band balun using composite right/left-handed transmission line

A wide-band balun is developed using a composite right/left-handed (CRLH) transmission line (TL) at 2 GHz. It is composed of a Wilkinson power divider and two phase-adjusting transmission lines, namely the CRLH TL and the conventional TL. The input reflection coefficient is better than -10 dB from 1 to 4 GHz. Over the frequency range of 1.24-3.58 GHz, an amplitude imbalance of less than 0.7 dB and a phase error of less than plusmn10deg have been experimentally demonstrated.