Experimental and theoretical investigations of new compact largebandwidth aperture-coupled microstrip antenna

The authors propose an efficient amelioration of the concept of large bandwidth aperture-coupled microstrip antennas by coupling a CPW line-fed slot to a microstrip antenna. The CPW fed aperture-coupled microstrip antenna investigated has a large bandwidth with high gain and low crosspolarisation levels, is compact with only one substrate, and may be easily connected to both passive and active components. A numerical model has been developed and the theoretical results are in good agreement with the experiments     

A beam steering antenna for X-band high power applications

There is a considerable interest in the antennas which have high power handling capacity with beam steering functionality. The design of narrow side waveguide slot-array antenna for high power applications is introduced in this paper. An approach to achieve a uniform radiation slot waveguide antenna is presented. The large scale array antenna can be composed of such antenna cells. Moreover, it is possible to realize beam steering in the azimuth direction by adjusting the broad wall dimension of the waveguide. Besides, this slot waveguide antenna is expected to have high power handling capacity in vacuum environment, because there is no dielectric or electric field enhancement inside the antenna.     

Millimeter-wave twin tapered-slot antenna

A millimeter-wave twin tapered-slot antenna on standard substrate is presented. The twin antenna is constructed by single tapered slot antennas (TSA), printed on opposite sides of a low dielectric constant (/spl epsiv//sub r/=2.2) substrate. The structure is fed by a rectangular waveguide followed by a broadband finline-to-slotline power splitter. The radiation pattern of the single TSAs is improved by corrugating the taper contour by a series of short-circuited stubs. With this method, antennas three times thicker compared with conventional TSA designs can be realized with an almost unchanged performance. Experimental radiation patterns of a 65-GHz twin TSA in comparison to both simulation results and corresponding single TSA measurements are presented. A measured twin antenna gain of 17.5 dB indicates efficient radiation.     

Wide-band slot antennas with CPW feed lines: hybrid and log-periodic designs

In microwave and millimeter wave applications, slot antennas fed by coplanar waveguide (CPW) lines are receiving increasing attention. These antennas have several useful properties, such as a wider impedance bandwidth compared to microstrip patch antennas, and easier integration of solid-state active devices. In this paper novel CPW-fed wideband slot antennas are presented. The design procedure of CPW-fed hybrid slot antennas (HSA) having impedance bandwidths (VSWR<2) up to 57% is described. Theoretical and measured results are shown. We also describe the design procedure of a CPW-fed log-periodic slot antenna (LPSA). The impedance matching and the radiation characteristics of these structures were studied using a method of moment technique. Simulated and measured results for different dielectrics are presented.     

一种新型 SIW 背腔缝隙天线的研究

介绍了一种新型基片集成波导背腔六边形缝隙线极化天线。背腔缝隙天线是一种技术成熟的天线类型,但是笨重的体积限制了传统金属腔体缝隙天线的发展。基于基片集成波导结构的背腔缝隙天线以其低损耗、高功率容量、高增益 以及易集成等诸多优点而备受关注。文中设计了一款基于基片集成波导加开六边形缝隙的背腔天线,通过CST软件仿真,并制作了天线实物进行测试。天线的中心工作频率为10 GHz,增益为4. 87 dB,带宽为147 MHz。     

CPW fed slot antenna with reconfigurable rejection bands for UWB application

A coplanar waveguide (CPW) fed ultra wideband slot antenna with reconfigurable band rejection characteristics is presented. Ultra wide bandwidth of 3.01–10.6 GHz is achieved by exciting the rectangular slot antenna with C-shaped stub. Band notch characteristic is changed between WLAN and WiMAX band by the integrated switches placed across the half wavelength slot. The performance of the proposed antenna is investigated numerically and experimentally. Experimental results demonstrate that the antenna exhibits omni directional characteristics with the peak gain of 4.9 dB and a gain variation of less than 2 dB across the operating band.     

CPW-fed log-periodic dumb-bell slot antenna array

A coplanar waveguide (CPW) fed log-periodic dumb-bell slot antenna array is presented. Due to the log-periodic structure and dumb-bell slot, the proposed antenna operates as a frequency independent antenna. The antenna is printed on a substrate with a single metal layer and therefore is easily constructed. The measured return loss and radiation patterns are also included.     

Study of a CPW inductively coupled slot antenna

Coplanar waveguide (CPW) fed slot antennas are attractive due to fabrication simplicity and ease of integration with active devices. A new concept for exciting slots with a CPW line based on inductive coupling is presented. It is described how this coupling structure can be designed to tune the impedance of the antenna over a wide range. Single elements and arrays designed for 5- and 25-GHz operation are described. Simulated and measured characteristics are presented. This new coupling topology is particularly suitable for series-fed array configurations and broad-band design     

Stacked patch antenna fed by a coplanar waveguide

A broadband patch antenna fed by a coplanar waveguide (CPW) is presented. The antenna was designed based on the stacked patch technique developed for aperture-coupled patch antennas. It is similar in configuration to a conventional stacked patch antenna, but the lower of its two patches is fed with a conductor-backed CPW Both simulation and measurement show that the antenna has bandwidth of over 10% (for |S/sub 11/| /spl les/ -10 dB) centred at 10 GHz.     

Single- and dual-polarized millimeter-wave slot-ring antennas

Single- and dual-polarized dielectric lens-supported slot-ring antennas have been developed for operation at millimeter-wave frequencies. The antennas are fed with a coplanar waveguide (CPW) to be compatible with uniplanar mixers and low-noise amplifiers, and the feedline is shown to have a minimal effect on the antenna performance. The measured antenna patterns agree well with theoretical results and have symmetric main beams, low sidelobe levels (<-15 dB), low cross polarization (<-20 dB), and 27 dB directivity. A 2×2 array of single-polarized slot-ring antennas for monopulse applications demonstrates excellent patterns at 94 GHz with -3 dB crossover power levels in both elevation and azimuth scans. The dual-polarized slot ring antenna patterns are nearly identical to those of the single-polarized antenna, and two-port isolation is as low as -25 dB. The dielectric lens-supported slot-ring antenna is an excellent candidate for compact, low-cost millimeter-wave systems with fixed or variable polarization capabilities     

Radiation of printed antennas with a coplanar waveguide feed

This paper presents an analysis of conductor-backed aperture antennas with multilayered substrate. These printed antennas are fed by a coplanar waveguide (CPW). The theoretical approach taken is to develop an integral equation over the aperture region and apply Galerkin's procedure in the spectral domain. The properties of printed antennas with a CPW feed are characterized. Numerical results include the scattering parameters, antenna pattern, and radiation efficiency. The reflection coefficient, input impedance, and far-field pattern are also compared with measurements and good agreement is observed     

一种提高微带MIMO 天线端口隔离度的新方法

多输入多输出(MIMO) 无线通信系统已经成为提高通信系统可靠性和数据传输速率的有效技术。MIMO 通信系统中,终端天线的性能对系统通信容量的提升至关重要。为了提高天线端口隔离度,提出了一种在微带天线辐射贴片上加载缝隙阵列实现天线极化分集,提高天线隔离度的方法,并且将这种方法应用于两个2 单元微带MIMO 天线设计中,取得了良好的效果。缝隙阵列加载不但抑制了微带MIMO 天线单元间的耦合,而且产生了更多谐振频点,改善了高频谐振频点畸变的天线辐射方向图,并且天线尺寸也得到了很大的减缩。最后对比分析了设计的两个微带MIMO 天线,实测结果与仿真计算比较可知,在工作带宽内,单元天线间耦合得到了非常有效的抑制。这种在平面天线辐射贴片加载缝隙阵列改变天线极化方向的技术可以很好地用来抑制多天线系统中单元天线间的耦合,而且对天线的其他性能不会造成影响。     

一种由渐变缝隙天线构成的等效全向天线

介绍了一种以斜角微带-缝隙过渡馈电的渐变缝隙天线。渐变缝隙天线具有平面结构、带宽较宽、增益适中等优点;斜角微带-缝隙过渡形式简洁,在工艺上易于实现。将几个这样的渐变缝隙天线以放射状构成一圈,并在它们的馈线上引入一组PIN开关,以适当的时序控制PIN开关依次切换,可构成一种等效的全向天线。这种天线结构简单,占用空间小,很适合弹载应用。     

CPW-fed circular slot antenna with slit back-patch for 2.4/5 GHz dual-band operation

A circular slot antenna fed by a coplanar waveguide (CPW) is proposed for dual-band operations. Dual frequency bands that cover the 2.4 GHz (2400-2484 MHz) and 5 GHz (5150-5825 MHz) bands were obtained by embedding a pair of slits in the circular back-patch that is printed on the backside of the substrate and concentric with the circular slot. This design resulted in broadside far-field patterns with low cross-polarisation levels in both frequency bands and a small antenna size of 40/spl times/40 mm with the ground plane regarded as part of the antenna structure.     

An Elliptical CPW Fed UWB Slot Antenna

A new CPW fed elliptical antenna for ultra-wideband (UWB) is proposed. The novelty of this antenna are very small size and uniplanar structure, which results in easy and low cost fabrication. This antenna has elliptical slot configuration which is fed by the CPW. This elliptical slot UWB antenna is enclosed in the extended surface of ground for decreasing the chip surface area. This antenna is designed with the optimal design parameters for the UWB spectrum. The designed antenna is printed on FR4 substrate and Vector Network Analyser is used for measuring return loss. The results of measurement results are similar to simulation results. The complete chip volume of antenna is 18.3?×?23?×?1.6 mm³.

     

共面波导馈电蝶形开口振子缝隙天线

讨论了共面波导(CPW)馈电蝶形开口振子缝隙天线。在缝隙振子天线两端加入蝶形开口结构,形成振子蝶形组合结构天线。使用有限元仿真软件(Ansoft HFSS)分析了设计的天线,结果表明组合结构天线具有振子天线与蝶形天线的优点:蝶形天线的宽带特性与振子天线的高增益特性,整个天线的性能得到提高。使用了两种馈电方式:感性耦合和容性耦合,感性耦合时组合天线的带宽特性较好,从振子天线5.9%提高到10.32%;容性耦合时增益特性较好,从振子天线的3.19dB提高至6.27dB。分析了衬底厚度对天线的影响,衬底厚度的增加使谐振频率降低,但对天线带宽的影响不大。     

小型化缝隙加载圆极化及宽带微带贴片天线设计

提出了一种十字形缝隙加载的小型宽带及圆极化微带贴片天线的设计方法。该天线通过在方形贴片上加载一个大尺寸的十字形缝隙实现天线的尺寸缩减,介质基片采用由FR4和空气层组成的层叠结构,在缝隙中嵌入L型枝节,只需通过调整枝节上同轴线馈电点的位置来获得圆极化或宽带阻抗匹配。ANSYS HFSS仿真分析表明,天线的圆极化带宽（AR≤3 dB）为1.7%,阻抗带宽（VSWR≤2）为5.8%,天线在宽带范围内具有稳定的增益,峰值增益为7.8 dB,同时贴片面积缩减了52.3%。改变馈电点的位置可调节两个谐振频率使天线阻抗带宽达到9.4%,比传统的微带贴片天线阻抗带宽提高了114%。     

Design of 45-degree Linearly Polarized Substrate Integrated Waveguide-fed Slot Array Antennas

This paper presents a method of designing substrate integrated waveguide-fed (SIW-fed) slot array antennas. The design theory is based on the circuit model of slot and via as well as the reflection canceling. To prove the feasibility of this method, a 10-element K-band SIW-fed 45-degree linearly polarized slot array antenna with uniform power distribution is designed. By full-wave simulation, the antenna has a good impedance bandwidth of 7.5% and uniform power distribution. Besides, a maximum gain of 15.3dBi is obtained in the broadside and the cross polarization is suppressed below -23.5dB in the boresight. This type of SIW-fed slot array antennas can be a good candidate for microwave and millimeter-wave applications, especially for auto-motive collision-avoidance radar systems.     

Design of the compact UHF RFID meander-line antenna loaded with CPW elements

In this paper, Coplanar Waveguide (CPW) elements are used to load UHF RFID meander-line antennas. Although, the insertion of these elements allow to design small antennas their gain decrease depending on the CPW structures are connected. In this sense, a new location to print CPW elements in the meander-line antenna is proposed aiming not to deteriorate the gain. A multi-objective optimization algorithm is applied in the meander-line antennas loaded with CPW elements in different positions and a comparison between their performances is done. To validate the computational model of the proposed antenna its input impedance is measured.     

对角馈电的SIW单腔体双极化领结形缝隙天线

多极化天线能够有效利用电磁波的空间维度,使无线通信或雷达系统容量得到很大提高。从对角馈电的基片集成波导腔体的场分布出发,分析其传输模式。通过在腔体表面设置正交缝隙,可以实现两种相互垂直的极化方式。在分析正交矩形缝隙和领结形缝隙的尺寸对天线性能影响的基础上,获取了TE120模谐振频率的经验计算公式,从而设计了两种双极化天线并比较了两者的工作性能。测试和分析结果表明,双极化领结形缝隙天线具有更大的带宽和更小的缝隙尺寸,测试的工作带宽为200 MHz,天线增益为5.2 dBi,具有广阔的应用前景。