一种结构新颖的半贴片宽带微带天线

设计了一种结构新颖的半贴片宽带微带天线。通过在圆形贴片上刻蚀两对环形槽,实现宽带特性,并在原有设计好的矩形贴片沿着馈电点所在的中轴线切掉一半贴片,减少了贴片一半面积,减小了尺寸。设计了这样一种半贴片宽带微带天线,不仅具有与原来全贴片基本相同的带宽特性,并且方向图与原天线基本相同,而且大大减小了天线尺寸。     

Small circularly polarised folded patch antenna

A small circularly polarised (CP) patch antenna with dual T-shaped probe feeds is presented. The patch is folded like a cap to generate a CP wave as well as to reduce the size of the antenna. The proposed antenna is operated at the centre frequency of 2.28 GHz with circular polarisation. The impedance bandwidth (SWR<2) is 21.8% from 2 to 2.49 GHz and the axial ratio bandwidth (AR<3 dB) is 3.5%. The measured gain is around 7.5 dBi. The antenna shows a good CP performance with a symmetric radiation pattern. The total area of reduction is 54% in comparison with the conventional half-wave patch antenna.     

Design of a broadband planar cavity-backed circular patch antenna

This paper presents a design of a low-profile cavity-backed circular patch antenna for broadband applications. By using substrate integrated waveguide (SIW) based cavity and feeding mechanism, a planar cavity-backed patch antenna is realized. The proposed study demonstrates that a wide impedance bandwidth can be achieved by employing a rectangular SIW-based cavity underneath the conventional circular patch. Additionally, to generate circular polarization (CP), the patch has been reduced diagonally and shorted by a via-probe. Finally, a CP SIW-based antenna is designed and operating for a wide impedance bandwidth of 23.10% below −10 dB criteria, ranging from 9.09 GHz to 11.40 GHz and axial-ratio (AR) bandwidth of 270 MHz (10.30–10.57 GHz). The proposed design is fabricated by means of a printed circuit board (PCB) procedure. The simulated results are validated with the experimental one which agrees well with each other in the terms of S₁₁, antenna gain, AR and radiation patterns. Moreover, the proposed design exhibits unidirectional radiation characteristics with the measured peak gain of 6.6 dBic while maintaining planar integration.     

Experimental study of directional aperture-coupled large-offset patch antenna with OS and BGP

A rectangular microstripline-fed directional aperture-coupled large-offset patch antenna with an open slot (OS) and a back ground plane (BGP), which has better radiation pattern properties, with the advantage of wider bandwidth than conventional structures, has been investigated. The large offset of the patch leads to enhanced bandwidth characteristic. The measured bandwidth of the antenna with an OS and the BGP is approximately 104% (2.0/spl ges/VSWR). The proposed antenna is not only more wideband but also has better radiation pattern characteristics than antennas with CS and BGP.     

Broadband patch antenna with low cross-polarisation

A broadband differential-fed patch antenna with good radiation pattern is proposed. Unlike conventional differential-fed patch antennas, the proposed antenna employs a folded plate pair as the differential feeding scheme. To demonstrate the devised feeding approach, impedance bandwidth of up to 74% (SWR<2) has been achieved. More importantly, symmetric radiation pattern, low-cross polarisation level and stable radiation pattern are realised within the band     

A wide-band monopolar plate-patch antenna

A new design of a monopolar plate-patch antenna is proposed and experimentally studied. The proposed antenna is a planar rectangular monopole top-loaded with a shorted square or circular patch, which is shorted to the antenna ground by two ground plates placed symmetrically on each side of the planar monopole. Prototypes have been constructed and experimental results show, that with an antenna height less than 10% of the free-space wavelength of the center operating frequency, the proposed antenna can have a monopole radiation pattern with an impedance bandwidth larger than three times that of a corresponding monopolar wire-patch antenna.     

A New Coupling Mechanism for Circularly Polarized Annular-Ring Patch Antenna

A novel coupling technique for circularly polarized annular-ring patch antenna is developed and discussed. The circular polarization (CP) radiation of the annular-ring patch antenna is achieved by a simple microstrip feed line through the coupling of a fan-shaped patch on the same plane of the antenna. Proper positioning of the coupling fan-shaped patch excites two orthogonal resonant modes with 90 phase difference, and a pure circular polarization is obtained. The dielectric material is a cylindrical block of ceramic with a permittivity of 25 and that reduces the size of the antenna. The prototype has been designed and fabricated and found to have an impedance bandwidth of 2.3% and a 3 dB axial-ratio bandwidth of about 0.6% at the center frequency of 2700 MHz. The characteristics of the proposed antenna have been by simulation software HFSS and experiment. The measured and simulated results are in good agreement.     

A monopolar patch antenna with very wide impedance bandwidth

A monopolar patch antenna that utilizes a bandwidth broadening technique is investigated experimentally and numerically. The proposed antenna consists of a monopole that is formed by connecting four trapezoidal plates orthogonally. A circular patch, which is shorted to the circular ground plane by four shorting wires, is placed at the top of the monopole. The antenna possesses 10-and 14-dB return loss bandwidths of 138% and 107.2% respectively, which is about 49 times that of the corresponding monopolar wire-patch antenna. Also, it provides monopole-like radiation patterns over such wide operating bandwidth. As the proposed antenna can achieve such wide impedance bandwidth with relatively low profile, it is very suitable for multi-band mobile communication systems.     

基于3D打印技术的宽带圆形微带天线

该文介绍了一款环形耦合的圆形贴片天线。采用圆形金属贴片作为天线的辐射贴片,通过在介质板上引入两个谐振环,产生两个新的工作谐振频段。通过调节圆形贴片和耦合环之间的高度,进一步拓宽了天线的工作频段。通过3D打印技术对不规则的介质基板进行加工制作,有效解决了传统加工方法加工难度大及生产周期长的问题。测试结果表明,该天线在3.8~5.8 GHz工作频段内,回波损耗小于10 dB;在5.1 GHz时,天线增益达到8.4 dBi;天线相对带宽为42%,且具有良好的全向辐射特性。天线的测试结果与仿真结果基本吻合。     

Broad-band single-patch circularly polarized microstrip antennawith dual capacitively coupled feeds

New design of a circular microstrip antenna with dual capacitively coupled feeds for broad-band circular polarization radiation is presented. The dual feeds are with a small top-loaded disk and are connected to a Wilkinson power divider with a 90° phase shift between its two output feedlines. The radiating circular patch, printed on a thin substrate, is supported by nonconducting posts on a conducting ground plane and is excited capacitively through the dual feeds. With a distance less than 10% times the center operating wavelength between the circular patch and the ground plane, the present proposed antenna can provide an impedance bandwidth (VSWR ⩽2) of about 49% and a 3-dB axial-ratio bandwidth of about 35%. The antenna gain bandwidth, defined to be within 1-dB gain variation in the axial-ratio bandwidth, is as large as 28%, with the antenna gain level at about 7.0 dBi     

A reciprocity approach for calculating the far-field radiationpatterns of a center-fed helical microstrip antenna mounted on adielectric-coated circular cylinder

This paper presents an efficient approach based on reciprocity for calculating the far-field radiation pattern of a center-fed helical microstrip antenna mounted on a circular cylinder. The reciprocity theorem is used to find a completely analytical solution to the problem assuming that the helical microstrip is sufficiently thin with a sinusoidal current distribution. Two degenerate cases of the helical microstrip antenna, i.e., an axially and an azimuthally fed half-wave cylindrical-rectangular patch, are examined and compared to known results in order to provide validation for the general analytical solution. Further comparisons are made between the analytical results and the results obtained using a numerically rigorous method of moments (MoM) computer code     

Ultra-Wideband L-Strip Proximity Coupled Slot Loaded Circular Microstrip Antenna for Modern Communication Systems

An analysis and design of a novel ultra wideband L-strip proximity coupled slot loaded circular microstrip antenna is proposed. The theoretical model is developed using circuit theoretic approach and obtained results are validated by MoM based IE3D simulation software. Theoretical results show a good agreement with simulated results. The patch is designed on a thick substrate of thickness 11 mm for a design frequency of 3.74 GHz and provides ultra wide band operation. The parametric study is carried out for return loss, radiation pattern, antenna efficiency, radiation efficiency and gain. It is observed that the bandwidth of the antenna depends on slot parameter and L-strip feed dimensions. An ultra bandwidth of 2.82 GHz is achieved with consistent radiation characteristics.     

一种新型小尺寸三陷波超宽带天线设计

文中提出了一种新型小尺寸具有三陷波特性的UWB天线。所设计的天线基本几何结构由50 Ω馈电线、圆形辐射贴片、缺陷地和一对开口谐振环组成,通过在天线的圆形辐射贴片上内嵌一对Y型贴片、地板上蚀刻出U型贴片和一对开口谐振环实现三陷波特性,天线的尺寸为30 mm×30 mm×16 mm。仿真和测试结果表明,该天线29~107 GHz的频段内回波损耗＜-10 dB,在37~42 GHz、515~5825 GHz和79~84 GHz3个频段内具有陷波特性,分别有效抑制了C频段的卫星系统、WLAN系统和X频段卫星系统对超宽带系统的干扰。在除3个阻带频段外的其余UWB工作频段范围内,有着良好的辐射方向特性和稳定的增益。仿真结果和实验结果表现出了良好的一致性。     

Broadband Patch Antenna With a Folded Plate Pair as a Differential Feeding Scheme

A broadband differential-fed patch antenna (DFPA) with good radiation pattern is proposed and studied. Unlike conventional DFPAs, the proposed antenna employs a folded plate pair as the differential feeding scheme. The devised feeding approach subtly acts as an impedance matching media for two radiation modes of the antenna, conducing to the wide impedance bandwidth. The conceived bandwidth enhancement technique demonstrates an impedance bandwidth (SWR les2) of up to 74% which outperforms conventional broadband patch antennas of more than 20%. Meanwhile, by using a differentially-driven signal along with the introduced feeding scheme, symmetric radiation patterns, low cross-polarization levels and stable radiation patterns are realized within the band. More importantly, the antenna has a stable gain at 8.5 dBi within a wide frequency range, demonstrating the high stability of the radiation characteristics for the two radiation modes. Analysis and parametric studies of the proposed feeding structure are provided.     

一种寄生阵列宽带圆极化天线的设计

该文设计了一款C波段单馈寄生阵列的宽带圆极化天线。此天线采用紧邻的双层F4B介质基板,通过在方形驱动贴片上开槽及采用寄生阵列的设计实现了圆极化。对天线结构的设计步骤进行说明,研究了各结构对天线阻抗带宽和轴比带宽的影响,并研究了寄生贴片切角长度和驱动贴片上的缝隙宽度对天线轴比和带宽的影响。对天线的圆极化方向图进行了仿真。仿真结果表明,在5.5 GHz时实现了右旋圆极化,最大增益为8.1 dBi。加工并测试了宽带圆极化天线,测试结果与仿真结果基本相符,天线实测的阻抗带宽为1.3 GHz,轴比带宽为1.26 GHz。设计的叠层天线具有结构紧凑,装配简单和轴比带宽大的优点。     

新型强耦合宽带双圆极化阵列天线

空间飞行器由于受到动力和负载的限制, 需要尽可能使搭载的天线轻质小型化.文中提出了一种新型强耦合双圆极化轻质天线.天线单元采用H型缝隙耦合和增加寄生贴片方法, 提高了天线带宽.同时, 通过在辐射贴片、寄生贴片上开圆形槽, 以及金属反射板栅格化的处理, 明显地减轻了天线的质量.采用这种新型天线单元, 设计了8单元的宽带双圆极化阵列天线.仿真结果表明:该阵列天线的中心频率为433 MHz, 左旋和右旋圆极化的相对轴比(Axial Ratio, AR)带宽(AR < 3 dB)分别达到了24.4%和23.2%, 有效实现了小型轻质化宽频带双圆极化阵列天线.     

微带线馈电的宽带单层贴片天线

微带贴片天线已广泛应用于雷达系统,文中介绍了一种新型背腔式单层微带贴片天线,辐射贴片采用微带线馈电,为增加工作带宽,提供了两种不同的贴片形状,第一种是E形贴片,仿真及测试结果表明,此种单元在驻波比优于2的条件下可实现45%的阻抗带宽,但该单元的波瓣带宽较窄。为抑制交叉极化,通过在E形贴片上开四个槽,得到了第二种改进的E形贴片。该单元可实现14%的频带内驻波比优于1.5,同时交叉极化优于-15dB。对C波段8×16单元实验小阵的测试结果表明,该天线在17.9%的频段内具有良好的交叉极化性能及较高的工作效率。     

一种新型圆极化贴片天线的研究

研究了圆极化微带贴片天线,通过在普通圆形贴片上开槽,提出了一种结构新颖的圆极化微带贴片天线.仿真以及实测结果表明,该天线具有较宽的3dB波瓣宽度(±50°)和良好的圆极化轴比性能,并且新型微带贴片天线的尺寸要远小于普通的圆形或圆环形贴片天线的尺寸.     

CPW feed circularly polarised microstrip antenna using asymmetric coupling slot

Design of a coplanar waveguide (CPW) feed square microstrip antenna with circular polarisation (CP) radiation is described. This CP design is achieved by using an asymmetric inductively coupling slot in the ground plane of the CPW feed line. Results show that the proposed antenna can have a CP bandwidth of 2.4%, whereas a simple inclined coupling slot case has 1.6% CP bandwidth at a fixed square patch size. Typical experimental results are presented and discussed     

Corrugated circular microstrip patch antennas for miniaturisation

New concepts for a corrugated circular microstrip patch antenna (CCMPA), which is moving in the radial direction and works at a frequency of 1.575 GHz (GPS), using linear and circular polarisation for miniaturisation are designed and fabricated. The linearly-polarised antenna has a reduction of 8.08% in patch diameter, a reduction of 21.12% in area and an increase of 1% in bandwidth compared with a circular microstrip patch antenna (CMPA). The radiation patterns of E-and H-plane for a corrugated-type antenna follow the general CMPA and the gain of the linearly-polarised antenna is 6.8 dBd. Also, the circularly-polarised antenna has a gain of 2.8 dBd and an axial ratio of 1.3 dBd at 1.575 GHz