Bow-tie slot antenna fed by CPW

A bow-tie slot antenna fed by CPW is introduced. It is designed to work in the Ku-band around 15.5 GHz. The proposed antenna is analysed both theoretically and experimentally. The presented results include the return loss and the radiation patterns. Two different geometries of the bow-tie antenna are presented and compared. The proposed antenna has several advantages such as a very large bandwidth, good control of its input impedance, and ease of fabrication. The proposed antenna has a dipole like radiation pattern which makes it suitable for mobile communication systems designed to work in the Ku-band     

一种双频双圆极化共面波导馈电缝隙天线

一种新型加载两个开口环形接地导带的双频共面波导（CPW）馈电缝隙天线,被提出来实现双旋向圆极化辐射。从天线信号带伸入槽隙的水平矩形调谐短截线用于改善频带内的阻抗和轴比。对天线进行仿真和实物测量。实验结果表明,该天线的10 dB 回波损耗阻抗带宽分别是,在1.55 GHz 频段为27.69％（1.4~1.85 GHz）,在2.55 GHz频段为26.17％（2.075~2.7 GHz）。在1.55 GHz的频段和2.55 GHz频段所测量的3 dB轴比带宽分别是20.51％（1.4~1.72 GHz）和13.44％（2.36~2.7 GHz）。其辐射极化方向分别是低频段右旋圆极化和高频段左旋圆极化,天线在两频段内的峰值增益分别是3.69 dB和3.81 dB。实物测试结果与仿真结果基本吻合。     

Waveguide slot antenna with a coupled dipole above the slot

The effect of a parasitic dipole above a waveguide slot antenna is shown analytically and verified experimentally. The E-plane radiation pattern is shown to be rather sensitive to the change of dipole length, and an equalised E- and H-plane pattern is obtained by choosing a proper length of dipole.     

Spectral domain analysis of a coupled slot antenna

The characteristics of a coupled slot resonator suitable for novel design of an integrated planar antenna are analyzed. The analysis is based on the spectral domain immittance matrix approach, and all the wave phenomena associated with the structure are incorporated. The resonant frequencies in the even and odd resonance modes are evaluated from the numerical solution of the characteristic equation, and the radiation patterns are calculated. The numerical results are compared with experimental data with good agreement     

CPW feed circularly polarised microstrip antenna using asymmetric coupling slot

Design of a coplanar waveguide (CPW) feed square microstrip antenna with circular polarisation (CP) radiation is described. This CP design is achieved by using an asymmetric inductively coupling slot in the ground plane of the CPW feed line. Results show that the proposed antenna can have a CP bandwidth of 2.4%, whereas a simple inclined coupling slot case has 1.6% CP bandwidth at a fixed square patch size. Typical experimental results are presented and discussed     

A compact CPW fed slot antenna for ultra wide band applications

A printed compact coplanar waveguide fed triangular slot antenna for ultra wide band (UWB) communication systems is presented. The antenna comprises of a triangular slot loaded ground plane with a T shaped strip radiator to enhance the bandwidth and radiation. This compact antenna has a dimension of 26 mm × 26 mm when printed on a substrate of dielectric constant 4.4 and thickness 1.6 mm. Design equations are implemented and validated for different substrates. The pulse distortion is insignificant and is verified by the measured antenna performance with high signal fidelity and virtually steady group delay. The simulation and experiment reveal that the proposed antenna exhibits good impedance match, stable radiation patterns and constant gain and group delay over the entire operating band.     

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.     

A new aperture coupled microstrip slot antenna

A new aperture coupled design is proposed for microstrip slot antennas to improve their radiation performance. The proposed design is based on a new aperture coupling technique in which the slot is fed by a microstrip line and coupled to several parasitic patch radiators etched on the opposite side from the slot. In contrast to the combination of a slot and a microstrip patch in conventional aperture coupled microstrip antennas, the patches here are employed to reduce the radiation into the half-space that they occupy and increase the radiation in the other half-space. Therefore, the slot antenna can produce radiation patterns with a high front-back ratio. The above objective is achieved by optimizing standing wave distributions of the aperture electric field in the slot through the adjustment of the position of the patches along the axis of the slot. In this paper, design considerations are given, and the results are validated by numerical simulations and experimental measurements.     

Transmission line analysis of nonlinear slot coupled microstrip antenna

The transmission line method is used for the analysis of microstrip antennas fed by several nonlinear slots with 'H' shapes or new geometries. This analysis allows the input impedance of nonlinear slot coupled microstrip antennas to be calculated for the four different structures.<>     

A twin slot antenna on a layered substrate coupled to a microstrip feed line

A method is described for calculating the input impedance as seen by the detector for a twin slot antenna structure. This technique is then used to analyze several twin slot antenna configurations, leading to improved performance.     

A dual polarized aperture coupled circular patch antenna using a C-shaped coupling slot

The design and development of a dual linearly polarized aperture coupled circular microstrip patch antenna at C-band are presented. The antenna uses a novel configuration of symmetric and asymmetric coupling slots. Variations in isolation between orthogonal feedlines and antenna axial ratio with the position of coupling slots are studied and broadband isolation and axial ratio are achieved. The prototype antenna yields 7.6 dBi peak gain, 70/spl deg/ 3-dB beam width, 25 dB cross-polarization levels and an isolation better than 28 dB between the two ports. With an external quadrature hybrid coupler connected to the two orthogonal feedlines, the antenna yields 3-dB axial ratio bandwidth of more than 30% at 5.8 GHz.     

Analysis of a slot microstrip antenna

The slot microstrip antenna is used as a folded slot dipole symmetrically fed across a gap by means of a strip line. A theoretical model equivalent to several lossy transmission lines had been described previously to explain the bandwidth and the radiation admittance. The theory is improved when coupling between the two equivalent radiating lines of every slot is taken into account, and explains a fourth resonance near the third one, which had been measured on several models. Theoretical results and experiments are in good agreement. They are radiation admittance in a wide frequency band, current distribution along each slot and radiation patterns.     

A back-to-back rectangular-patch antenna fed by a CPW

The configuration of a back-to-back rectangular-patch antenna fed by a coplanar waveguide (CPW) is proposed. The characteristics of the proposed antenna element were clarified by experiments. The radiation patterns and input impedances were measured as parameters of the widths of the rectangular patch and the substrate. Experimental results for an array antenna using the proposed back-to-back rectangular-patch antenna element are described. Good omnidirectional radiation patterns and input impedance characteristics were obtained. The proposed array antenna is suitable for microcellular, wireless LAN, and indoor radio systems     

一种改进的U型槽超宽带微带天线研究

设计了一种改进的U型槽低剖面宽带微带天线,并考虑在尺寸为30.0 mm×30.0 mm×1.5 mm、由相对介电常数为4.4的FR4制成的覆铜介质基板上通过酸蚀制备该天线。利用仿真软件HFSS对该天线的参数进行了仿真和优化,并根据优化的天线尺寸进行了实际制作和测量。仿真及实测结果均表明:通过在U型槽臂加载弧形,该天线的频带宽度和相对带宽分别可达3.4～11.2 GHz(S11≤–10 dB)和107%,达到了展宽带宽的目的。该天线不仅可以实现超宽带,而且结构简单,尺寸小,易于集成。     

CPW bandstop filter using periodically loaded slot resonators

A new dual-spiral-shaped slot resonator in a coplanar waveguide (CPW-DSR) is studied. Also, its equivalent circuit model is introduced and used for multi-resonant performance analysis. Finally, a bandstop filter using periodically loaded CPW-DSRs is presented and verified by simulations and measurement.     

Broadband CPW fed stacked patch antenna

A broadband CPW fed stacked patch antenna well suited for integration with monolithic and optical integrated circuits is presented. The antenna is designed with a bandwidth of 40% on a high dielectric constant feed substrate. The predicted and measured input impedance and far field radiation patterns are given     

共面波导差分馈电频率可重构天线

提出了一种共面波导(coplanar waveguide, CPW)差分馈电频率可重构天线.通过直流偏置电路来控制天线上四个PIN二极管的导通和断开模式, 天线可以工作在两种状态, 实现在2.02~2.89 GHz和3.27~3.66 GHz两个频段的重构, 阻抗带宽分别为35.4%和11.3%, 且天线辐射方向图受频率可重构的影响较小, 天线在两种状态下的平均增益分别可达3.18 dBi和3.61 dBi.该天线充分利用共面波导天线结构简单和频带宽的优势, 实现了差分馈电技术与频率可重构技术的完美结合.天线的实测结果与仿真结果非常接近, 可应用于WLAN的2.45 GHz和WiMAX的2.45 GHz、3.5 GHz两个频段.     

一种小型宽频带缝隙天线的设计

设计一种结构新颖紧凑的小型宽频带(带宽10 GHz)微带天线。以24 mm×23 mm×1.6 mm的FR4为基底,在基底接地面中心位置设计一个正六边形和一个对称的十字交叉型贴片组成的缝隙来增大工作带宽,基底另一侧是一条微带线。用电磁仿真软件Ansoft HFSS对该天线进行模型仿真和结构优化,并进行加工和测试。结果显示该天线工作频段覆盖3.6～13.6 GHz,阻抗带宽为116%,辐射特性良好,给出了反射损失曲线和辐射方向图,测试结果与仿真结果基本相同,为宽频带无线通信的研究提供了一定的参考。