Single-feed slotted equilateral-triangular microstrip antenna forcircular polarization

Novel designs of single-feed equilateral-triangular microstrip antennas for circular polarization (CP) are proposed and studied experimentally. It is demonstrated that by embedding a narrow slot or a cross slot of unequal slot lengths in the triangular patch, circularly polarized radiation of microstrip antennas can easily be achieved using a single probe feed. Furthermore, results show that for the design with a cross slot, the proposed antenna can perform CP radiation with a reduced antenna size at a given frequency (denoted as compact CP operation here); that is, the required antenna size is smaller for the proposed antenna for performing CP radiation as compared to a conventional circularly polarized triangular microstrip antenna at a fixed operating frequency. Details of the proposed CP designs are described, and typical experimental results are presented and discussed     

基于领带结Sierpinski分形结构的RFID标签天线

基于三角形Sierpinski微带分形贴片,提出了一种新型的小尺寸领带结RFID标签天线设计。通过仿真,给出了该分形天线的端口特性,同时给出了该领带结型Sierpinski标签天线的谐振频率、方向图以及天线效率。结果表明,采用不同维数的分形结构,可以实现多频段的工作特性,因而该天线可以很方便地应用于RFID电子标签中。     

Novel dual-frequency and broad-band designs of slot-loadedequilateral triangular microstrip antennas

By loading properly arranged slots in an equilateral-triangular microstrip patch, novel dual-frequency and broad-band operations of a single-feed triangular microstrip antenna are presented. For dual-frequency operation, the proposed design is achieved by loading two pairs of narrow slots in the triangular patch, one embedded close to the side edges of the patch and the other inserted at the bottom edge of the patch. The obtained two operating frequencies are of same polarization planes and by varying the positions and lengths of the inserted slots at the bottom edge of the patch, a tunable frequency ratio of the two frequencies ranging from about 1.16 to 2.06 is obtained. Furthermore, it is found that by protruding a narrow slot out of the embedded slots close to the side edges, broad-band operation of the triangular microstrip antenna near its fundamental resonant mode can be achieved. Results show that the antenna bandwidth of the proposed broad-band design can be greater than 2.6 times that of a conventional triangular microstrip antenna. Details of the proposed dual-frequency and broad-band designs are described and typical experimental results are presented and discussed     

Gain enhancement of a circularly polarized equilateral-triangular microstrip antenna with a slotted ground plane

A novel circular polarization (CP) design of a single-feed equilateral-triangular microstrip antenna with enhanced antenna gain is presented. This CP design is obtained by placing three triangular slots at properly locations below the equilateral-triangular radiating patch in the ground plane. By adjusting one of the triangular slot's side lengths slightly longer than that of the others, two orthogonal near-degenerate resonant modes for CP radiation can be excited. Measured antenna gain in this study can easily be increased by 3.3 dBi (5.1 dBi versus 1.8 dBi), as compared to the same height, substrate material, operating frequency and radiating patch shape of a regular equilateral-triangular microstrip antenna without triangular slots in the ground plane. Prototype antenna is fabricated for experimental evaluation. Simulated and measured results are presented.     

Broadband triangular microstrip antenna with U-shaped slot

The broadband design of a triangular microstrip antenna with a U-shaped slot is demonstrated. With a foam substrate of thickness ~0.08 λ₀, a slotted triangular microstrip antenna with an operating bandwidth of ~18% is obtained, which is ~1.8 times that of a corresponding simple triangular patch antenna. Details of the antenna design and experimental results are presented     

Comments on “On the resonant frequencies of microstripantennas”

The resonant frequencies of equilateral triangular microstrip antenna calculated by Gang (see ibid. vol.37, no.2, p.245, 1989) are compared with the experimental results of Dahele and Lee (1987). When computing the resonant frequencies of equilateral triangular microstrip antenna, using the same equations proposed by Gang, we obtained different results, which are given, from Gang's results. For an equilateral triangular microstrip antenna, the resonant frequencies obtained from the cavity model with perfect magnetic walls are given by the formula shown. In this work, we suggest a new closed-form expression. We compared our computed values of the resonant frequencies for the first five modes of the equilateral triangular patch antenna with theoretical and experimental results reported by other scientists     

微带印刷天线辐射与散射的全波分析方法

本文给出了一种分析微带印刷天线辐射与散射的数值方法。此方法将印刷天线按三角网格剖分，在导体表面建立积分方程，用全波离散镜像理论给出微带结构的空域格林函数的闭合表达式，未知电流用三角网格上的矢量电流基函数展开并用矩量法求解。与以往的矩形网格上基函数展开相比，此方法能更有效地逼近任意形状的微带结构，最后给出了几个数值结果     

Compact circular polarisation design for equilateral-triangularmicrostrip antenna with spur lines

A novel compact circular polarisation (CP) design for a single feed equilateral-triangular microstrip antenna with inserted spur lines at the patch edges is presented. It is found that, with increasing spur-line length, the resonant frequency of the triangular microstrip patch is significantly lowered. Also, by further adjusting the inserted spur lines to have a length ratio of ~0.96, the proposed design can achieve CP radiation at a much lowered operating frequency, resulting in compact triangular microstrip antennas with circular polarisation     

一种新型宽频带三角形微带天线的设计

提出了一种展宽三角形微带天线工作带宽的新方法。通过在三角形微带贴片加载与侧边平行的缝隙来实现双频,添加垂直于底边的缝隙使两个频点靠近,经仿真软件优化后,最终实现频带展宽。仿真结果表明,所设计天线的工作带宽(VSWR<2)是普通三角形微带天线的4倍,且天线尺寸与同频率未加载缝隙的天线相比缩小5%。进行了实物加工与测量,实验结果与仿真结果吻合,证明了所提出方法的有效性。     

Compact shorted variations of triangular microstrip antennas

Equilateral and triangular 30°-60°-90° microstrip antennas have been modified by shorting along the zero field to yield shorted 60 and 30°-sectoral microstrip antennas, respectively. Experimental results on these antennas are presented. The shorted 60 and 30°-sectoral antennas result in area reduction by factors of 2.5 and 5.0, respectively, compared to the equilateral triangular antenna with the same resonant frequency. The frequency is further reduced by partially shorting the curved edges of the sectoral antennas     

Single-feed circularly polarized equilateral-triangular microstripantenna with a tuning stub

Novel circular polarization (CP) designs of single-feed equilateral-triangular microstrip antennas are proposed and experimentally studied. The proposed CP designs can easily be achieved by loading a narrow tuning stub at the triangle tip or at the center of the bottom edge of the triangular patch. Moreover, by embedding a cross-slot of equal slot lengths in the triangular patch, a compact CP operation can easily be obtained, with an antenna size reduction up to about 22%, as compared to the CP design of a regular triangular microstrip antenna without cross-slot at a fixed frequency     

磁性基片双频三角形微带贴片天线

采用国内首创的新型有机磁性材料做基片，提出一种创新设计实现了微带贴片天线的双频工作。这是通过在三角形微带贴片的底边加载矩形凹槽来实现的，结构简单且双频比易于调节。由于采用了新型磁性基片，使天线尺寸比相同频率的常规贴片天线缩小，而具有比常规微带天线宽得多的带宽。文中给出了仿真和实测结果，证明了设计的有效性．     

Bandwidth enhancement of inset-microstrip-line-fedequilateral-triangular microstrip antenna

By embedding a pair of properly-bent narrow slots in an equilateral-triangular microstrip patch, broadband operation of microstrip antennas with an inset microstrip-line feed can be achieved. With the proposed antenna design, the impedance bandwidth can be as large as ~3.0 times that of a corresponding simple triangular microstrip antenna. Some simple design rules for the proposed antenna have also been determined experimentally. The design rules and experimental results are presented and discussed     

Low-profile design of dual-frequency and dual-polarised triangular microstrip antennas

A single-feed triangular microstrip patch antenna that can be operated at two distinct resonant modes is proposed. The two resonant modes can radiate an omnidirectional dipole-like pattern with linear polarisation and a broadside pattern with circular polarisation, respectively. To achieve the required frequency ratio of the two operating frequency bands, several designs of the proposed antennas with different substrate thickness and patch sizes are studied. In addition, these designs can easily obtain a 50 /spl Omega/ input impedance without any additional matching circuit. Details of the antenna design and obtained performance are presented.     

多层微带贴片天线单元和阵列设计

该文通过结合经验公式和全波分析法,设计了一种电容补偿双层贴片、四层介质的微带贴片天线单元,该单元天线在频率为995～1125MHz的范围内,在驻波比SWR1.5的情况下,相对阻抗带宽达到12.26％的工程要求。此外,该文给出由该单元天线组成的216天线阵以及天线阵的驻波比的实测结果,最后给出天线阵的各单元排列方式和单元之间的互耦特性曲线的实测结果。     

Simple and accurate formula for the resonant frequency of theequilateral triangular microstrip patch antenna

An approximate solution of the capacitance of a circular microstrip disk to account for the fringing fields is used for calculation of the resonant frequency formula of the equilateral triangular microstrip patch antenna. The theoretical results are in good agreement with experimental data     

Single-feed square-ring microstrip antenna with truncated cornersfor compact circular polarisation operation

A novel circular polarisation (CP) design of a single-feed square ring microstrip antenna with truncated corners is described. Experimental results show that the proposed design has a reduced antenna size as compared to the conventional circularly-polarised square microstrip antenna with truncated corners at a given operating frequency. Also, the required size of the truncated corners for CP operation is larger for the present design than for the conventional design using a square microstrip patch, which suggests that the fabrication tolerance is relaxed for the present design. Typical results are presented and analysed     

Fractal volume antennas

The fractal volume antenna concept is introduced in order to increase the degree of design freedom associated with fractal antenna elements and hence improve their input matching characteristics. Practical examples are given involving the Sierpinski triangular gasket monopole and a novel Sierpinski carpet gasket microstrip antenna. The scope for further optimisation and some manufacturing aspects are noted     

Wideband single-fed circularly polarised patch antenna

A novel circularly polarised (CP), single-fed microstrip antenna is presented. The antenna consists of a stacked structure of almost square patches. The proposed design has a reduced antenna size compared to the conventional CP microstrip antenna at a given operating frequency. The impedance and axial ratio bandwidths are large and CP radiation quality is excellent over the entire upper hemisphere. The proposed antenna is suitable for global positioning system (GPS) applications.     

Hybrid-coupled broadband triangular microstrip antennas

Two broadband configurations consisting of three hybrid-coupled equilateral and isosceles triangular microstrip antennas have been proposed. Both configurations yield more than four times the bandwidth as compared with the corresponding single triangular microstrip antenna. The radiation pattern of a hybrid-coupled isosceles triangular microstrip antenna is in the broadside direction with very small variation over the entire bandwidth. In addition, this antenna has wide half power beamwidth, making it suitable as an element for the large scan broadband antenna array.