FDTD analysis of CPW-fed folded-slot and multiple-slot antennas onthin substrates

Folded slot antennas are attractive for active arrays due to relatively large bandwidth, fabrication simplicity, and ease of integration with devices. Currently, there is little design information for these antennas, especially on thin substrates. The finite-difference time-domain (FDTD) method is applied to the analysis of CPW-fed folded-slot antennas. The paper describes the problems encountered in the analysis, compares the theoretical results and measured data, and provides some design information for folded slots. In addition, it explores the manipulation of input impedance through the use of additional slots, yielding antennas with a broadband 50 Ω input impedance     

CPW-fed oscillating microstrip antennas

Operating with a low-cost FET, oscillating CPW-fed microstrip antennas working at ~4 GHz have been presented. Because the design is based on slot or slot loop apertures, no via holes are required, These oscillating antennas are compact, easy to fabricate while providing uniform radiation patterns with cross-polarisation levels below -17 dB. Active integrated power combining arrays or active integrated phased arrays are possible future applications of these radiating elements     

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。     

79 GHz Slot Antennas Based on Substrate Integrated Waveguides (SIW) in a Flexible Printed Circuit Board

The design, fabrication and characterization of 79 GHz slot antennas based on substrate integrated waveguides (SIW) are presented in this paper. All the prototypes are fabricated in a polyimide flex foil using printed circuit board (PCB) fabrication processes. A novel concept is used to minimize the leakage losses of the SIWs at millimeter wave frequencies. Different losses in the SIWs are analyzed. SIW-based single slot antenna, longitudinal and four-by-four slot array antennas are numerically and experimentally studied. Measurements of the antennas show approximately 4.7%, 5.4% and 10.7% impedance bandwidth (${rm S}_{11}=-10$ dB) with 2.8 dBi, 6.0 dBi and 11.0 dBi maximum antenna gain around 79 GHz, respectively. The measured results are in good agreement with the numerical simulations.      

Microstrip leaky-wave antenna fed by short-end CPW-to-slottransition

Single and dual-beam microstrip leaky-wave antennas fed by a short-end coplanar waveguide (CPW)-to-slot transition are presented. The radiation bands of the antennas are deduced from the leaky-wave propagation characteristics of the microstrip line first higher order leaky mode. The measured reflection coefficients of the radiation band confirm the predicted leaky band and the measured radiation patterns exhibit the frequency-scanning feature of the leaky-wave antenna. The short-end CPW-to-slot transition feeding method simplifies the circuit layout and is more suitable for different band design than the CPW-fed microstrip first higher order leaky-wave antennas presented in the literature     

Wideband CPW-fed slot antenna for DCS, PCS, 3G and Bluetooth bands

A novel CPW-fed wide planar slot antenna with an asymmetrical slot is proposed. The asymmetrical slot is square-like with the same widths but different lengths at the sides. By choosing suitable lengths of this asymmetrical slot, broadband operation can be obtained. From experimental results, the measured impedance bandwidth, defined by 10 dB return loss, can reach an operating bandwidth of 2136 MHz with the centre frequency operating at 2610 MHz for applications to various wireless bands. In addition, the measured radiation patterns within this wide impedance bandwidth have the same polarisation planes and similar radiation characteristics. Each antenna gain within the application bands can be less than 1 dB     

Moment method analysis of infinite stripline-fed tapered slotantenna arrays with a ground plane

A full-wave method of moments solution for infinite arrays of stripline-fed tapered slot antennas is described. The formulation of the problem is sufficiently general to permit performance evaluation of most of the geometries that have been proposed for stripline-fed antennas as well as of several other types of array antennas. Computed results for some well-known antenna arrays are presented to demonstrate the validity and accuracy of the method. Excellent agreement with published results has been obtained for scattering from corrugated surfaces and grounded dielectric slabs and for the input impedance of dipole and monopole arrays. Catastrophic effects such as scan blindness are accurately predicted. A sample result showing the measured and computed input impedance of a stripline-fed tapered slot antenna array is also presented     

具有任意斜缝的微带缝隙天线研究

本文利用谱域方法和互易定理,建立了具有任意斜缝的微带缝隙天线的一般化求解方程,并用矩量法求其数值解。文中给出了天线输入阻抗随缝隙倾斜角变化的数值结果,最后给出了3GHz频段的设计曲线。     

Design of aperture-coupled annular-ring microstrip antennas for circular polarization

The design of an aperture-coupled annular-ring microstrip antenna for circular polarization (CP) is presented. The CP radiation of the annular-ring microstrip antenna is achieved by a series microstrip-line-feed configuration through the coupling of a ring slot in the ground plane. The key parameters of the proposed design are investigated using a commercial simulation software based on the Method of Moments to show how to obtain the 50 /spl Omega/ input impedance and optimum axial ratio. The proposed design can be applied to the annular-ring microstrip antennas with different inner radii and substrate thickness, and several antenna prototypes are constructed and measured. Details of the experimental results of the CP performance are presented and discussed.     

Miniaturised CPW-fed circularly polarised corrugated slot antenna with meander line loaded

A novel CPW-fed circularly polarised antenna with corrugated structure and meander line loaded is presented. This antenna can achieve 44% size reduction compared to the conventional CPW-fed slot antenna. Predicted results are validated by experiment. The measured 3 dB axial ratio bandwidth and the 10 dB return loss bandwidth are 12.4 and 17.1%, respectively. The peak gain of the antenna is 4.0 dBi.     

共面波导馈电宽带矩形边蝶形缝隙天线的仿真分析与设计

对一种共面波导馈电的宽带缝隙天线进行了仿真分析。着重研究了共面波导馈线各参数的变化对天线阻抗性能的影响,总结出了相应的规律和参数选取准则。根据分析结果,给出了合理调节共面波导馈线的参数以提高缝隙天线的阻抗性能的方法,并利用所得到的变化规律,给出了该天线的一种宽频带设计方案。     

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     

Impedance matching of tapered slot antenna using a dielectrictransformer

A new impedance matching technique for tapered slot antennas using a dielectric transformer is presented. The technique is demonstrated by measuring the input impedance, VSWR and the gain of a Vivaldi antenna (VA). Measured results at Ka-band frequencies are presented and discussed     

共面波导馈电的带阻UWB天线设计

提出了共面波导(CPW)馈电平面圆形单极子带阻超宽带(UWB)天线的设计方法,采用该方法设计的天线满足超宽带无线通信所要求的3.1 GHz~10.6 GHz的频带范围,通过在圆形贴片上添加U形和弧形缝隙,可分别实现4.75 GHz~5.96GHz范围内和4.8 GHz~6.2 GHz范围内电压驻波比VSWR≥2的带阻特性,均避免了5 GHz无线局域网的干扰。采用电磁仿真软件CST进行了天线的方向图绘制,仿真结果表明该设计可行。     

Analysis and design of broad-band single-layer rectangular U-slot microstrip patch antennas

A wide operating bandwidth for a single-layer coaxially fed rectangular microstrip patch antenna can be obtained by cutting a U-shaped slot on the patch. This antenna structure has recently been found experimentally to provide impedance bandwidths of 10%-40%, even with nonair substrates. However, design rules for this antenna have not yet been presented. This paper develops principle design procedures through examination of the structure's multiple resonant frequencies as well as the radiation and impedance properties of different antenna geometries. The approximate design rules are derived by analysis of former experiments, method of moments (MoM) simulations, and measurement results. Simulations and measurements of several antennas designed using these new rules are presented and directions for further study are discussed.     

Wideband CPW-Fed Spiral-Shaped Slot Antenna for Wireless Applications

A new compact design of CPW-fed wideband (WB) spiral-shaped slot antenna is proposed. The proposed antenna has a compact size with overall dimensions 37-33 mm and is fabricated on FR4 substrate with dielectric constant ? _r = 4.4 and thickness h = 1.6 mm. With the different length of the spiral-shaped slots, simulated and experimental results of the antenna are suitable for WB operations. The–10 dB bandwidth of the WB antenna from measurement is approximately 115.2% (2.36–8.53 GHz). The proposed antenna provides nearly omni-directional radiation characteristics. The new antenna configuration operates in several different bands: 2.4, 3.5, 5.2, 5.5, and 5.8 GHz covering 2.4/5.2/5.8 GHz WLAN bands and 2.5/3.5/5.5 GHz WiMAX bands. The results for S₁₁, far-field H- and E-plane radiation patterns and gain of the proposed antennas are presented and discussed. The agreement between measured results and full-wave simulation validates the feasible configuration of the proposed antennas.     

Broadband printed CPW-fed circular slot antenna

A broadband printed CPW-fed circular slot antenna is proposed. This antenna is composed of a circular slot fed with a 50 /spl Omega/ CPW line through a circular patch. A parametric study was carried out to optimise the proposed structure, and the simulated and measured results show that the proposed design offers an ultra-wide bandwidth of 143.2% (from 2.3 to 13.9 GHz).     

基于互补分裂谐振环的十字缝隙贴片天线（英文）

A compact patch antenna is designed, which is with structures of cross-shape slot, Complementary Split Ring Resonator(CSRR), and loaded transmission line. To implement the compactness in size, these structures are etched on the ground plane, then the input impedance has been improved. The CSRR is employed to improve impedance matching between the source and radiation patch, and the cross-shape slot on the radiation patch is utilized to increase the bandwidth. The design is validated by compariso...     

Bandwidth enhancement of a printed wide-slot antenna with small slots

In this paper, four printed wide-slot antenna fed by a microstrip line with a polygonal slot for bandwidth enhancement is proposed and experimentally studied. One of these antennas is fabricated and measured. Impedance, radiation and gaincharacteristics of this antenna are presented and discussed. From experimental results, the measured impedance bandwidth, defined by 10-dB return loss, can reach an operating bandwidth of 4.03 GHz at operating frequencies from approximately 1.87 to 5.90 GHz.     

Bandwidth enhancement and further size reduction of a class of miniaturized slot antennas

In this paper, new methods for further reducing the size and/or increasing the bandwidth (BW) of a class of miniaturized slot antennas are presented. This paper examines techniques such as parasitic coupling and inductive loading to achieve higher BW and further size reduction for this class of miniaturized slot antennas. The overall BW of a proposed double resonant antenna is shown to be increased by more than 94% compared with a single resonant antenna occupying the same area. The behavior of miniaturized slot antennas, loaded with series inductive elements along the radiating section is also examined. The inductive loads are constructed by two balanced short circuited slot lines placed on opposite sides of the radiating slot. These inductive loads can considerably reduce the antenna size at its resonance. Prototypes of a double resonant antenna at 850 MHz and inductively loaded miniaturized antennas at around 1 GHz are designed and tested. Finally the application of both methods in a dual band miniaturized antenna is presented. In all cases measured and simulated results show excellent agreement.