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     

基于FDTD的微带漏波天线分析的新方法

使用时域有限差分法对微带漏波天线进行数值仿真,得到了微带漏波天线TE01模下的电场分布,对微带漏波天线的电波传播特性进行初步的讨论.提出新的经验计算公式微带漏波天线漏波传播系数,所得漏波传播系数曲线与实测数据以及比较数据十分吻合.     

Surface wave excitation on a microstrip ring antenna

A theoretical analysis of the excitation of surface waves on a microstrip ring antenna is presented. The problem is formulated using dyadic Green's functions in a layered medium with magnetic-type equivalent current sources. The integral equation for the fields is solved in the wave number complex plane so that the fields from space and surface waves are obtained separately. The space wave radiation efficiency is calculated for the TM₁₁, TM₁₂, and TM₁₃ modes for various values of the normalized dielectric substrate thickness, d/λ₀. It is noted that the TM₁₃ mode radiates more efficiently than the TM₁₁ and TM₁₂ modes. The results are of importance in the design of these antennas     

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     

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。     

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.     

一种微带线馈电的宽带圆极化微带天线的设计

提出一种微带线馈电的宽带圆极化微带天线,它由微带馈线、辐射贴片和FR4介质板组成,在辐射贴片的矩形槽对角添加两个环形结构,实现了微带天线圆极化的要求,通过调整微带馈线的尺寸,有效改善了天线的轴比带宽。该天线单元的轴比带宽达到了43.8%(2.5~3.9 GHz)。     

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.     

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.     

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     

超宽带微带天线的波概念迭代法分析

随着无线通信系统的快速发展,具有宽带宽、增益高、尺寸小的超宽带微带天线受到广泛的关注。利用波概念迭代法(WCIP)结合传输线理论仿真了双层和三层结构的超宽带微带贴片天线,计算了该天线的回波损耗、驻波比等参数;对比分析了WCIP在计算效率上的优势;分析了电路层数对天线带宽的影响,发现增加电路层数是天线带宽展宽的一个有效途径。同时,与软件HFSS仿真结果的对比验证了WCIP分析微波多层电路的正确性和有效性。     

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.<>