UWB Metamaterial-based miniaturized planar monopole antennas

In this paper, ultra wide band (UWB) metamterial based compact planar antennas have been designed and experimentally verified. Four novel unit cells have been realized and each unit cell dispersion characteristics are numerically calculated which follows CRLH-TL properties. These four CRLH-TL unit cells are loaded into monopole antennas which result, four open-ended MTM antennas respectively. Further, a novel via free version of CRLH-TL unit cells have been designed, which increases the fabrication flexibility. The compactness has been achieved by realizing ZOR (zeroth order resonance) mode and its bandwidth is increased by realizing small shunt capacitance and large shunt inductance. Further, by optimizing CRLH-TL unit cells, two closely spaced zeroth-order and first-order resonance modes are merged into a single pass band, which gives wide bandwidth. The each proposed antenna has a compact dimension of 0.27 λ₀ × 0.19 λ₀ × 0.02 λ₀ (22 × 15 × 1.6 mm³), where λ₀ is a free space wavelength at 3.8 GHz. The four proposed antennas have S₁₁ < −10 dB impedance bandwidths of 8.4 GHz, 8.5 GHz, 8.2 GHz and 8.3 GHz respectively. The optimum gain, good efficiency, desired radiation characteristics in frequency domain analysis and less distortion of waves in time domain analysis have been achieved for proposed antennas, which are most suitable for UWB applications. The CST-MWS has been used for the parametric study of the proposed antennas. A good agreement has been observed between simulated and experimental results.     

平面超宽带天线的设计与研究

提出了两种新型的平面超宽带(UWB)天线,这两种天线的馈电单元和辐射单元都采用了矩形与圆形的组合结构,使得天线的工作带宽展宽.通过数值分析和实验结果表明,两种天线可获得较宽的工作带宽,能满足UWB天线3.1～10.6GHz的带宽要求.同时,具有良好、稳定的全向辐射特性和较高的增益,有较好的实用价值.     

一种双阻带椭圆单极子UWB天线的设计

通过仿真与实际测试结合的方法,研究并设计了一种用于UWB通信的、具有双阻带特性的紧凑椭圆单极子天线。双阻带特性是通过在辐射单元上插入一个缝隙和在馈线上引入一共面波导谐振单元实现的。测试结果表明此天线在3.45~3.75 GHz(覆盖了WIMAX频段)和5~6 GHz(覆盖了5.15~5.85 GHz的WLAN频段)分别有两个阻带,此外,驻波系数在3.1~10.6 GHz UWB的范围内小于2。天线的辐射特性也近似于全向。天线的增益和传输函数也证实了天线能达到双阻带特性。     

Wide-band planar monopole antennas

The circular disc monopole (CDM) antenna has been reported to yield wide-impedance bandwidth. Experiments have been carried out on a CDM that has twice the diameter of the reported disc with similar results. New configurations are proposed such as elliptical (with different ellipticity ratios), square, rectangular, and hexagonal disc monopole antennas. A simple formula is proposed to predict the frequency corresponding to the lower edge of the bandwidth for each of these configurations. The elliptical disc monopole (EDM) with ellipticity ratio of 1.1 yields the maximum bandwidth from 1.21 GHz to more than 13 GHz for voltage standing wave ratio (VSWR)<2     

一种超宽带地板开槽单极子天线的设计

研制了一款超宽带印刷单极子天线。通过在接地板和单极子贴片底部开槽,展宽了天线频带,改善了天线带内特性,提高了天线增益。采用HFSS软件进行仿真,对天线模型参数进行优化,达到最佳设计效果。结果表明,改进后的天线-10 dB阻抗带宽为2.2~14.6 GHz,比原不开槽天线的-10 dB阻抗带宽增加了7.2 GHz。天线实现了小型化超宽带的同时,在整个超宽带匹配频段内,具有良好的驻波和方向图特性,在超宽带设备中有着很好的应用前景。     

Multiband multiple ring monopole antennas

This paper proposes two novel designs of a multiband antenna using multiple rings. The first design consists of a set of self-similar circular rings. This is an alternative to the recently reported triangular fractal Sierpinski gasket monopole antenna, and comparison is made to this and the circular disk monopole antenna. The second design is realized by varying the shape of the circular structure to an elliptical one. Larger bandwidth and improved patterns are achieved. In comparison to the circular disk, improved radiation pattern control at higher operating bands, due to the discrete structure of the multiple rings, is shown by numerical and experimental results. The bandwidth is significantly larger than the Fractal Sierpinski gasket and Parany monopole.     

Wideband double-fed planar monopole antennas

Planar monopole antennas with multiple feed points are proposed to improve pattern and impedance bandwidth. A square planar monopole antenna including two feed points and a bevelled variant are designed. These antennas exhibit an excellent performance compared to existing planar monopoles     

Retro-transceiver array using monopole antennas

In this paper, we show how a self-tracking antenna array constructed using λ/4 monopoles can be constructed, which is capable of receiving with gain over an entire 360° azimuthal cut. It is also shown how the self-tracking receive unit can be used in conjunction with a self-phased transmitter so that self-steered spatially selective receive and transmit functions can be formed simultaneously. The resulting array is capable of maintaining spatially selective receive and transmit functions to a roaming target without prior knowledge of its physical location     

快速计算套筒单极子天线

利用矩量法分析计算套筒单极子天线的电性能参数。采用与实际天线较为接近的矩量法分析模型和一种新的粗圆柱线天线快速精确计算模型,大大提高了分析计算的精度;引入「Ｚ」矩阵插值法,提高了分析计算的速度。将该方法与最优化技术相结合,设计出一付工作在２００～７００ＭＨｚ频段、ＶＳＷＲ〈２．６、增益Ｇ〉５．１ｄｂ的实用套筒单极子天线,理论分析与实验测试吻合良好,从而说明了该方法的有效性和实用性。     

Spline-based geometry for printed monopole antennas

A novel Bezier spline-based geometry for printed monopole antennas is presented. Quadratic curves are used to describe the outline of the radiating element. The geometry is optimised by a genetic algorithm. A small number of control points are used to define the geometry, ensuring a small search space for the GA. The resulting antenna has an impedance bandwidth from 1.44 to 14.7 GHz     

Crosspolarisation for monopole antennas on limited ground planes

The crosspolarised radiation from monopoles on square ground planes of side 0.5 to 2.2? has been investigated. The radiation pattern structure and the relative strength of the crosspolar radiation are described.     

Compact UWB monopole for multilayer applications

A novel compact, dual-layer UWB monopole antenna is presented. This low profile ultra-wideband antenna is fed by a 50 /spl Omega/ shielded strip-line with an array of metal vias making the conducting walls. A printed disc monopole with a circular cut is the radiating element. The dual-layer, shielded strip-line feed allows for integration in multilayer technologies. The ultra-wideband, monopole characteristics of the antenna are confirmed experimentally     

Design and analysis of planar monopole antennas using a genetic algorithm approach

The application of genetic algorithm (GA) optimization to the design and analysis of planar monopole antennas is presented. GA is first used to optimize the impedance matching bandwidth of two particular planar element shapes, the bow-tie (BT) and reverse bow-tie (RBT). The results of this study indicate that the RBT can achieve a significantly wider bandwidth with a much smaller size than the traditional BT. In a follow-on study, GA is used to generate arbitrarily shaped planar monopole designs, which exhibit improved broadband performance and/or reduced size compared with the RBT. The designs generated by the GA demonstrate a better tradeoff between matching bandwidth and electrical size compared with planar monopole designs previously characterized in the literature. Analysis of results from simulation and measurement are presented, which provide insight into the operation of these antennas as well as the key parameters that lead to improved performance. Finally, a performance bound is generated to relate the bandwidth limitation of planar monopoles to size.     

一种椭圆单极子超宽带天线仿真设计

随着宽带无线通信的发展,宽带天线的研究已成为行业研究的热点,通过对多种单极天线研究,选择了平面椭圆单极子宽频天线进行了设计,并对接地板进行切角处理和各项参数分析与优化,实现了宽频天线的性能要求。与其他各种设计相比,其结构简单,制作方便。     

Impedance characteristics of planar bow-tie-like monopole antennas

The impedance characteristics of planar bow-tie-like monopole antennas have been studied experimentally. The planar bow-tie-like monopole antenna achieves a broad bandwidth, typically of >75%. A modified formula is suggested to accurately evaluate the frequency corresponding to the lower edge of the impedance bandwidth     

Small-sized low-profile antenna to replace monopole antennas

The authors compare the operating characteristics of a compact flat plate antenna with those of a classical quarter-wavelength monopole for portable telephone applications. Similar performances are obtained for both antennas, proving that the low-profile antenna offers an attractive alternative to other monopolar antenna structures for small-sized transceiver units     

Wideband monopole antennas for multi-band wireless systems

The planar monopole antenna is shown to provide extremely wideband impedance characteristics. Recently, many techniques to tailor and optimize the impedance bandwidth of these antennas have been investigated. These include the use of bevels, slots and shorting posts. These antennas are becoming popular, and have been proposed for modern and future wideband wireless applications. The radiation performance is also shown to be acceptable over a wide frequency range.     

30 GHz self-assembled highly-efficient on-chip monopole antennas

A novel monopole antenna made from an out-of-plane stressed cantilever beam is presented. The radiating element is isolated from a low-resistivity silicon substrate with a ground plane and thus high radiation efficiency of more than ∼50% can be achieved even with a CMOS-grade silicon substrate. The proposed antennas can be readily fabricated by a conventional IC fabrication process, which enables a high level of integration and low cost. Our experimental results of the monopole operating at 30 GHz agree well with our theoretical predictions.     

Novel bi-arm rolled monopole for UWB applications

This work presents a bi-arm rolled monopole for ultrawide-band (UWB) applications. The roll monopole is constructed by wrapping a planar monopole. The impedance and radiation characteristics of the proposed roll monopole are experimentally compared with a rectangular planar monopole and strip monopole. Furthermore, the transfer responses of transmit-receive antenna systems comprising two identical monopoles are examined across the UWB band. The characteristics of the monopoles are investigated in both time and frequency domains for UWB single-band and multiple-band schemes. The study shows that the proposed bi-arm rolled monopole is capable of achieving broadband and omnidirectional radiation characteristics within 3.1-10.6 GHz for UWB wireless communications.     

Numerical analysis of collinear monopole antennas with coils

Double-band operation (85 and 900 MHz) of a collinear monopole antenna is numerically demonstrated. The antenna consists of three linear wires connected with two coils, and has a height of 67 cm. One coil acts as a phase compensation element to increase the gain and the other as a decoupling element for use in the mobile telephone band.<>