一种新型小型化微带天线的全波分析

本文介绍了一种新颖的小型化微带天线.利用在贴片上面开一个C型缝隙,使得谐振频率明显降低,尺寸仅是传统的半波长微带天线的33%,阻抗带宽略有增加,并且加工相对简单.利用时域有限差分法(FDTD)对这种天线进行了较为全面的理论分析,给出了输入端反射损耗特性和辐射特性.同时给出了矩量法(MoM)分析结果和测量结果,具有较好的一致性.此种天线可应用于对天线尺寸有严格限制的场合.     

Broadband quasi-microstrip antenna

A new printed microwave antenna is presented. The antenna is a hybrid between a wire antenna array and a microstrip patch antenna. Although the size, cost, and efficiency are comparable to the microstrip patch, the voltage standing wave ratio 2:1 bandwidth of the antenna presented here is above 20%. The radiation pattern of the antenna does not change appreciably within the bandwidth, and the theoretical efficiency for optimal antennas remains above approximately 80% within the bandwidth. Measurements on several antennas around 2 and 4 GHz are presented, as well as theoretical results obtained using a full-wave analysis     

单馈电双模方形微带天线及圆极化实现收稿

基于展开理论,给出了沿贴片对角线馈电时方形微带天线的内场分布和输入阻抗公式.通过在贴片四周切割缝隙,有效地降低了天线双主模的谐振频率并实现了圆极化辐射,讨论了缝隙长度与天线极化之间的关系.为实现微带天线的小型化提供了一种新途径,给出了UHF波段天线设计实例.     

Distance-measurement error associated with antenna phase-center displacement in time-reference radio positioning systems

This paper presents a tutorial discussion of the effects of antenna phase-center displacement on distance determination in time-correlation radio positioning systems. A technique to determine the antenna phase-center displacement as a function of observation angle is reviewed. A simple method to determine the distance error versus observation angle, derived from the antenna phase-center displacement, is then presented. Numerical distance-error predictions, determined directly from antenna phase-center displacement, are presented for a Yagi and a log-periodic antenna used in a commercial UHF radio distance-measurement system. Finally, the measured distance error versus observation angle for these antennas as determined in several field trials is presented, validating the numerical predictions.     

雷达导引头天线技术发展趋势探讨

基于现代雷达技术的发展和应用,详细分析了雷达导引头天线技术的发展趋势。由于雷达导引头对天线性能的特殊需求,在回顾反射面天线技术的发展过程的基础上,着重探讨了阵列天线技术,包括波导裂缝阵天线技术、有源相控阵天线技术以及共型天线阵技术在雷达导引头中的应用,从而对其发展趋势进行了探讨和分析,非线性有源天线阵技术的出现将会极大地推动导引头相控阵天线技术的发展。     

Electromagnetically coupled coaxial dipole array antenna

A new type of collinear antenna called electromagnetically coupled coaxial dipole array antenna is proposed. The antenna has an advantage of structural simplicity due to a novel use of an electromagnetically coupled feed structure for the radiating element. An analysis of the radiating element is presented and compared with experimental results. Fabrication and measurement of a prototype array antenna are also presented     

A study of the quadrifilar helix antenna for Global PositioningSystem (GPS) applications

An analytic model for computing the radiation properties of the quadrifilar helix volute antenna is discussed and various design considerations for GPS applications are presented. The effects of modifying the antenna length and diameter on the antenna amplitude and phase performance are presented, and using the antenna for dual-frequency operation is discussed. The effects of phase imbalances are presented and compared with measured pattern anomalies     

Design method of Yagi-Uda two-stacked circular loop array antennas

A design method which works as a single balanced feed antenna is presented for the Yagi-Uda two-stacked circular-loop array antenna. The antenna is analyzed with a theoretical model consisting of loop elements and feeder sections. The results are compared with experiments. By using the computed and measured antenna currents, the gain enhancement of the antenna is confirmed to be due to both the stacked-loop-array and endfire-array effects. A method of compensation for the reflection loss and a design procedure are discussed in detail. A graphical method is given to estimate the optimum size of the antenna without detailed numerical calculations, and the performance of the designed antenna is demonstrated by experiments. Experimental results are presented for several antennas arranged with different numbers of loops in the endfire and broadside directions     

Antenna system for measuring electromagnetic field parameters

A functional block diagram of the general-purpose antenna system for measuring electromagnetic wave parameters has been presented. Theoretical relationships forming a basis of the antenna system structure are described, and the antenna operation principle is presented.     

Analysis and optimization of an electrically small receivingantenna

A theoretical and experimental study of an optimum receiving antenna configuration that fits within certain allocated space requirements is presented. This optimum monopole antenna configuration is applicable for Loran-C reception. The antenna analysis is based on a quasi-static numerical study of a conducting body of revolution above a perfectly conducting ground plane. A general numerical algorithm is developed to determine the input impedance and the effective height of the antenna. In addition, the amplifier noise and its role in the choice of the optimum antenna are examined. Results are presented for cylindrical and truncated conical structures both with and without a top load     

A new method for obtaining antenna gain from backscattermeasurements

A method is presented for determining the gain of an antenna from analysis of backscatter data of the antenna. This approach is different from those which have been presented in the past because it accounts for the presence of resonances which can occur in the antenna during a backscatter measurement. In particular, this type of resonance appears in the backscatter measurement of symmetric reflector antennas. This technique is applied to determine the gain of a Ka-band Cassegrain antenna and an X-band prime focus-fed antenna     

一种基于电磁超材料的抗干扰天线

设计了一种基于电磁超材料的抗干扰天线.该抗干扰天线由矩形波导腔体,铺设于波导腔体底部宽边的电磁超材料以及位于波导腔体上部宽边的辐射缝隙构成.当电磁超材料表现为完美电导体时,该抗干扰天线同传统波导缝隙天线类似,可高效辐射电磁波.当电磁超材料表现为完美磁导体时,该抗干扰天线的性能与带阻滤波器相似,可抑制特定频段的干扰电磁波.该抗干扰天线实现了天线与滤波器的高度集成,结构紧凑.仿真与测试结果显示该抗干扰天线在工作频段具有良好的辐射特性,同时对干扰频段电磁波的抑制可达40 dB.     

Time domain analysis for foldable thin UWB monopole antenna

In this paper, the time domain analysis of an Ultra Wide Band antenna flexible circular monopole antenna is presented. The antenna is fabricated on liquid crystalline polymer flexible substrate with a compact geometry that makes it suitable for wearable applications under different bending conditions. The antenna is fed by coplanar waveguide transmission line and has a compact total size of 40 × 22 mm². Moreover, the antenna has good radiation efficiency (97%) over the bandwidth. The presented antenna has a good performance over the operating spectrum for straight and bending configurations. The design principals along with simulation and experimental results are presented in this contribution.     

Broadband dual frequency microstrip antenna

A new dual port microstrip antenna geometry for dual frequency operation is presented. The structure consists of the intersection of two circles of the same radius with their centres displaced by a small fraction of the wavelength. This antenna provides wide impedance bandwidth and excellent isolation between its ports. The gain of the antenna is comparable to that of a standard circular microstrip antenna operating at the same resonant frequency. A theoretical analysis for calculating the resonant frequencies of the two ports is also presented     

A new planar grating-reflector antenna

A planar grating-reflector antenna with frequency-scanning properties is presented. The antenna system is composed of a point feed and a planar reflector consisting of a frequency-scanned reflection grating. The grating geometry must be selected such that the first higher-order diffracted wave propagates and serves as the frequency-scanned beam. A focus feed position for the diffracted field is obtained by allowing the lattice geometry to vary along the reflector surface. Methods for analyzing and designing the new antenna configuration are presented. The antenna concept is demonstrated theoretically and experimentally by the design, evaluation, and test of an experimental antenna operating over the frequency band 9.5-10.5 GHz     

An EIA/CEA-909 compatible smart antenna system for digital terrestrial broadcasting applications

This paper discusses the theory and design of a smart antenna system for receiving digital terrestrial television signals. The pertinent antenna theory and the associated hardware is presented as is the relationship between the two. Finally, field results using digital terrestrial television signals are presented to evaluate the performance of the smart antenna system.     

Compact stripline-fed meander slot antenna

A meander-type slot antenna fed by a stripline is proposed for use in miniaturised personal communication systems. By varying the slot configuration of the antenna, a 56% smaller antenna to substitute the conventional slot antenna is achieved. Simulated and measured results are presented     

抗干扰天线及天线阵列研究

本文对抗干扰天线及天线阵列进行了研究,提出了一种小型化的微带贴片天线,并使用该天线单元进行组阵。文中提出的立体天线阵列的主天线单元实现了宽波束和在低仰角方向上增益的改善,能够满足工程应用的需要。     

Compact Dipole Antenna for Terrestrial Digital Multimedia Broadcasting Service

A compact dipole antenna for the terrestrial digital multimedia broadcasting (TDMB) application is presented. The length of the antenna is about 0.06λ at the TDMB resonance frequency of 190 MHz. Miniaturization of the antenna is achieved by using meander structures and lumped elements. The proposed antenna has two resonance frequencies and covers the TDMB band from 174 MHz to 216 MHz in Korea. The antenna has good impedance bandwidth and radiation characteristics for the TDMB. The experimental results of the designed dipole antenna are presented and analyzed.     

A new quasi-Yagi antenna for planar active antenna arrays

In this paper, a novel broadband planar antenna based on the classic Yagi-Uda dipole antenna is presented, and its usefulness as an array antenna is explored. This “quasi-Yagi” antenna is realized on a high dielectric-constant substrate, and is completely compatible with microstrip circuitry and solid-state devices. This antenna achieves a measured 48% frequency bandwidth for voltage standing-wave ratio <2, better than a 12-dB front-to-back ratio, smaller than -15 dB cross polarization, and 3-5-dBi absolute gain. Mutual coupling of the antenna in an array environment is investigated. Finally, three simple arrays are presented, demonstrating the usefulness of the antenna as an array element. This novel antenna should find wide application in wireless communication systems, power combining, phased arrays, and active arrays, as well as millimeter-wave imaging arrays