无表面波损耗的孔耦合贴片天线的设计

设计了一种新结构的孔耦合贴片天线。该天线结构将贴片连用制作贴片的介质基板一起放置在一个矩形金属框里,彻底阻断了表面波的传输,该天线结构的尺寸比一般贴片天线要小很多。但却具有更高的增益,还介绍了对该天线结构的数值模拟。样品制作和实验测量,测量数据显示矩形金属框使天线的增益在9GHz到11GHz的频率范围内平均提高了0.7dB,该天线的工作频带超过了20%,带内平均增益为8.3dBi,同时天线具有良好的辐射方向图。     

Aperture-coupled microstrip line leaky wave antenna with broadsidemainbeam

A microstrip first higher order leaky wave antenna (LWA), centre-fed by an aperture-coupled microstrip with a broadside mainbeam, is presented. The measured bandwidth (23% for VSWR<2:1) is in agreement with the leaky radiation band predicted. The experimental gain patterns, compared with those of a patch antenna fed by the same type of structure, reveal the difference between these two kinds of antenna. With increasing frequency, the radiation field of the LWA spreads into the H-plane, forming a flatter broadside pattern, which can be applied to long rectangular area communication     

毫米波微带天线阵列设计

设计了一个圆口径串并联混合馈电的毫米波微带天线阵列。该天线采用矩形微带工字型缝隙贴片耦合馈电的方法展宽带宽。为了有效利用天线口径面积,减小网络复杂度,选取串联微带天线阵列形式。同时为了展宽带宽,根据设计的圆形口径阵列,将部分子阵采用串并联混合馈电的形式,得到带宽为5%的毫米波微带天线阵列。仿真表明,该天线在工作频带内增益大于30.6 d Bi,波束宽度为4.0°×3.5°,副瓣电平低于–13 d B。该天线阵面与网络配合,可以实现多波束或相控阵的功能。     

Circular polarization microstrip antenna on a conical surface

A theoretical model to analyze the performance of a circular polarization microstrip antenna printed on a conical surface is presented. The radiation pattern of the antenna is simulated by the radiation from its four radiating edges (two axial and two circumferential). The electromagnetic field is expanded in terms of spherical wave modes and it is shown that the circular polarization is obtained by exciting in the antenna two spherical TE_r orthogonal modes with 90° phase difference. The impedance analysis is based on the cavity model. Experimental data fits well the theoretical predictions of the model     

角馈微带天线的全波分析

利用积分方程法对角馈型微带天线进行了分析,对其中的奇异振荡函数积分,给出了有效的数值积分方法。数值实验证明了该方法的有效性。同时,给出了角馈微带天线的输入阻抗特性,方向图特性和带宽特性。     

Micromachined microstrip patch antenna with controlled mutualcoupling and surface waves

Silicon micromachining has been used to demonstrate the possibility of building high performance microwave and millimeter-wave antennas. To suppress higher order substrate modes and increase the bandwidth of a patch antenna, silicon substrate has been used and material has been selectively removed under the patch area. In addition, the effect of etched grooves around a patch element has been studied for performance improvement, it has been shown that micromachined substrate structure can effectively suppress unwanted surface wave modes resulting in improved radiation efficiency. Moreover, effective dielectric constant curves for the shielded micromachined substrates are provided for accurate design of patch antennas. We have demonstrated that mutual coupling between the radiating patch elements due to surface waves can be controlled using various micromachined substrate configurations     

Transmission line analysis of aperture-coupled microstrip antenna

The authors present an original analysis of a slot-coupled microstrip antenna. The transmission line model uses previous expressions of conductance and susceptance due to the fringing fields near the edges of the patch; moreover, a simple interpretation of the different impedance transformations is given. Results based on the transmission line model are compared with other theoretical analyses (cavity model, moment method) and measurements.<>     

Global electromagnetic analysis of microstrip agile antenna

A global electromagnetic analysis of microstrip agile antennas is presented. The analysis developed is based on the integral equation technique associated with a numerical treatment of lumped elements, which enables the actual size of the varactor diodes to be taken into account. The agreement between theoretical and experimental results clearly shows the capabilities of this approach to predict the agility phenomenon     

Compact reflective microstrip phase shifter for traveling wave antenna applications

A varactor diode based microstrip phase shifter for 5.8GHz is presented. It is designed for use in microstrip traveling wave antennas where there is a strict limitation on the available space for the phase shifters. To meet all requirements, a reflective type phase shifter is chosen. Such a phase shifter includes a hybrid coupler. A compact branch line coupler is designed to make the phase shifter fit between the radiating elements in the antenna, while maintaining sufficient electrical performance. Phase shifters are designed with different types of stubs connecting the diodes to ground. A phase tuning range of 62/spl deg/ is measured for a phase shifter with parallel open stubs, and 92/spl deg/ with shorted stubs. Insertion loss is in both cases less than 0.6dB. A complete five-element array antenna is built and characterized. Measurements show beam scanning angles within /spl plusmn/32/spl deg/ from broadside.     

一种毫米波微带双频天线阵的设计

文章阐述了利用3个T型功分器设计一个4×1的毫米波微带双频并馈天线阵方案,该双频天线阵的中心频率在32 GHz和35.36 GHz左右,运用Ansoft HFSS软件进行仿真测试,天线阵的增益方向图说明该天线阵主要的辐射方向是上半空,天线阵在32 GHz的增益为12.62 dB,在35.36 GHz的增益为10.72 dB。     

Computer analysis method for arbitrarily shaped microstrip antenna with multiterminals

An analysis method is presented for an arbitrarily shaped microstrip antenna with multiterminals. The method is based on the variational method and the modal-expansion technique. Eigenvalues and eigenfunctions are determined using the Rayleigh-Ritz method. Input impedance and other antenna parameters are derived at nonresonance. Furthermore, the network model, useful for the network analysis of a microstrip antenna with multiterminals, is presented by introducing an ideal transformer. Finally, numerical examples are compared with experimental results. The agreement is quite good, and the validity of the present method is confirmed.     

Self-adjusting microstrip antenna

A microstrip circuit operating in the G band is presented. It allows all emitting printed antenna to self-tune its resonance frequency when it is disturbed, in order to stay resonant and matched at the desired transmit frequency. The principle, design and experimental results of the circuit are presented     

人工磁导体在缝隙耦合微带天线中的应用

研究了一种由人工磁导体(Artificial Magnetic Conductor,AMC)构成的缝隙波导传输线技术在缝隙耦合微带天线中的应用.在通信频段,分析了构成AMC单元结构的色散特性.结果表明:在缝隙耦合微带天线背面加入AMC,可以降低背面辐射效应,优化天线的性能.     

Compact microstrip antenna with dual-frequency operation

The characteristics of a single-feed dual-frequency compact microstrip antenna with a shorting pin are studied experimentally. Besides the compactness of the antenna, this dual-frequency design can provide a high frequency ratio of >3.0 between the two operating frequencies. Typical experimental results of the proposed antenna are presented and discussed     

Reconfigurable microstrip antenna with polarisation diversity

A single probe-fed reconfigurable microstrip patch antenna with symmetric cross slots is proposed. By controlling four pin diodes on the patch slots, the proposed antenna has right hand circular polarisation, left hand circular polarisation or linear polarisation.     

蝶形微带天线的全波分析与宽带设计

介绍了蝶形微带贴片天线的一种全波分析方法－矩量法,与多端网络法相比,其适应范围更广。然后介绍了展宽天线频带的一种设计方法。通过不对称馈电方式,激励起两个相近频率的模式,从而使微带天线驻波比带宽获得明显展宽。测试结果与计算结果相当吻合,证实了数值分析与设计方法的有效性。     

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.<>     

基于平面微带结构超介质天线设计与分析

利用开槽曲流技术构建了一种工作频段位于S、C波段内的多频微带贴片天线,根据传统立体左手材料的变型结构设计了一种新型平面微带结构的超介质。在微带贴片天线的介质基板内加载超介质覆层后,天线工作频率降低,频带展宽以及辐射性能得到改善。HFSS和Matlab仿真实验结果表明,新型平面微带结构的超介质在2.7~4.9GHz和5.0~5.5 GHz两个频段内具有等效介电常数和等效磁导率均小于0的左手特性,工作频率在2.66,3.67,4.66和5.49 GHz的微带贴片天线加载超介质覆层后,其谐振频率分别降低了140,140,210和270 MHz,同时4.60~4.78GHz的工作频带展宽了160 MHz。该超介质微带天线可以运用于实际的WLAN或WIMAX通信中。     

Modal expansion method of analysis for slot-coupled microstrip antenna

A modal field expansion technique together with the Poynting theorem are used to derive the input impedance of a slot-coupled microstrip antenna. The approach leads to easier and lower computational requirements. Predicted values of input impedance are compared with previous theoretical and experimental results.<>     

矿井下射频识别天线的损耗分析

通过巷道电磁波传输损耗公式分析了矿井中影响传输损耗的三个因素。以工作频率为为2.45GHz的RFID微带天线为实例,借助仿真软件HFSS和MATLAB得出影响传输距离的主要因素是巷道的倾斜角度。