基于SIW 的多波束CTS 阵列天线设计

文中设计了一款基于基片集成波导(SIW)的毫米波高增益多波束连续横向枝节(CTS)阵列天线,它 通过切换馈电端口实现多波束功能。该天线整体结构简单,采用印刷电路板工艺实现。天线主要包含馈电喇叭、平 面波转换结构以及辐射结构三个部分,由三层基板构成。馈源为基于SIW 的馈电喇叭,并在口径处添加匹配结构以 提高其辐射性能;平面波转换结构由SIW 抛物面和渐变耦合槽组成,可将馈电喇叭辐射出的柱面波转换为幅度服从 泰勒分布的平面波进而为CTS 阵列馈电,因此天线具有低副瓣的特性;辐射结构为1×8 的CTS 阵列,通过优化缝隙 宽度以保证每个单元辐射出相等的能量。天线工作在30 GHz,通过切换馈电端口可在±20°范围内实现波束切换,天 线测试结果与仿真结果吻合,验证了设计的合理性。     

Parametric analysis of flare edge rolling throat bending and asymmetric flare effects for H-plane horn radiator

In this paper, radiation characteristics of H-plane sectoral horn antenna are treated systematically by investigation of main structural design parameters and, flare edge rolling, throat bending and asymmetric flare effects. The analytical regularization method (ARM) is used to solve the problem of E-polarized wave diffraction in a fast and accurate way. The numerical procedure is initially verified by the analytical solutions, and then the calculated directivity gain patterns are demonstrated for the modeled horn antenna configurations. Proper choices of the antenna parameters, such as horn depth, aperture length, feeder waveguide width, flare angle, wall thickness, flare edge rolling and throat bending are proposed for the designers to reach high directivity gain, narrow beam width, suppressed side lobe levels, increased front-to back ratio and improved aperture efficiency.     

Minor lobe suppression in a rectangular horn antenna through the utilization of a high impedance choke flange

A significant reduction in the minor lobe radiation pattern of a rectangular pyramidal horn antenna is obtained by placing a choke around the aperture of the antenna and adjusting the choke to approximately a quarter wave in depth. The reduced minor lobe radiation means less scattering and a higher efficiency. The choke also results in an improvement in the antenna gain with a measurably narrower beam. A minor variation of approximately 10 percent, peak to peak, is obtained in the antenna input impedance for choke depths varying from zero to a quarter of a wave.     

Quad Band Substrate Integrated Waveguide Cavity Backed Slot Antenna Using Balanced Shorting Vias

In this paper, low profile cavity-backed cross shaped slot antenna using substrate integrated waveguide (SIW) technology is proposed for obtaining quad-band response. In order to generate four distinct frequencies, a crossed slot is etched on the back of the dielectric substrate and three balanced shorting vias (metallic vias) are included across the longitudinal slot. Furthermore, the electric field distribution has been utilized for understanding the working principle of the proposed design. Balanced shorting vias modify the current distributions of the cavity, which consequently produces two resonant frequencies in X-band and two more resonant frequencies in Ku-band. Finally, the proposed quad-band antenna is fabricated using printed circuit board (PCB) technology and the results are experimentally verified. With the height of 0.026λ₀, the measured results show that the proposed design resonates at 8.6 , 10.2 , 13.2 , and 14.8 GHz and exhibits a –10 dB impedance bandwidth more than 150 MHz at corresponding frequencies. The proposed antenna attains a peak gain of more than 6 dBi at the corresponding resonant frequencies, respectively. Those amicable characteristics, e.g., low profile, uni-directional radiation pattern, ease of fabrication, quad-band response and moderate gain, make the proposed antenna suitable for both radar and satellite systems.

     

基于基片集成波导馈电的Ka波段渐变缝隙天线设计

在被动毫米波 (PMMW) 成像焦平面阵列 (FPA) 馈源的天线中,直线渐变缝隙天线 (LTSA) 相对于传统的喇叭天线、介质棒天线具有其独特的优势。该文优化设计了一种新型的对跖直线渐变缝隙天线 (ALTSA),通过加载超材料结构使天线的增益得到了改善,天线采用基片集成波导 (SIW) 技术进行馈电。通过仿真与测试分析,该天线在较宽的频带内具有良好的阻抗特性、较低的副瓣电平及较高且平稳的增益,所设计的天线具有较小的口径宽度,在焦平面中易于组成较为密集的馈源阵列,以提高被动毫米波成像的空间分辨率。     

Filtenna Consisting of Horn Antenna and Substrate Integrated Waveguide Cavity FSS

An integrated module with filtering and radiation performance realized by covering substrate integrated waveguide (SIW) cavity frequency selective surface (FSS) at aperture of horn antenna has been investigated in this paper. The module has functions of bandpass filter and horn antenna, so it is called a "filtering antenna" (filtenna). It is very suitable for applications in military platforms where FSS is used for antennas and radars' radar cross section (RCS) reduction. The filtenna is simulated and optimized with CST software and its performance is verified by experiments. From simulated and measured results it can be found that the proposed structure keeps characteristics of return loss, radiation pattern and gain of the horn antenna within desired frequency band, meanwhile presents effective reflection to interference signals at out-band. Using this structure the volume and cost of communication systems in military platforms can be effectively reduced     

SIW cavity-backed circularly polarized square ring slot antenna with wide axial-ratio bandwidth

In the proposed work, Substrate Integrated Waveguide (SIW) cavity-backed circularly polarized slot antenna for wideband operation is proposed. A square-ring-slot is etched on the top of the SIW cavity, used for radiation To generate the circularly polarized (CP) wave, the slot is placed slightly offset from the centroid of the cavity. By finely optimizing the antenna dimensions, it exhibits a wide axial-ratio (AR) bandwidth of 789 MHz (7.1%) ranging from 10.64 to 11.45 GHz. Moreover, the radiating slot is excited by an SIW based feed by an inductive window, which lead to a wide impedance matching over 1.74 GHz ranging from 9.92 to 11.67 GHz. Due to the SIW cavity-backing structure, the antenna offers unidirectional radiation patterns while maintaining a low-profile and planar compatibility. To validate the proposed design, the antenna is fabricated and experimentally tested in terms of reflection coefficients, AR, gain, and radiation patterns. The simulated and measured results reveal good mutual agreement. Moreover, the proposed antenna is very useful for wideband applications operating in X-band (8–12 GHz)     

A radiometric antenna gain calibration method

A radiometric method is presented for measuring the power gain of a microwave antenna. It is particularly applicable to horns with gains in the range 20-45 dB, and an absolute uncertainty (3sigma) of less than 0.1 dB is achievable in favorable cases. An absorbing screen with a circular aperture is placed in the far-field of the test antenna. The diameter of the aperture is chosen to subtend an angle much smaller than the main lobe of the radiation pattern of the test antenna. Then two sheets of microwave absorber (one at ambient temperature and the other cooled to the boiling point of liquid nitrogen) are alternately placed first behind the screen aperture and then, for normalization, across the aperture of the test horn. The ratio of the antenna temperature differences measured with a sensitive microwave radiometer is proportional to the effective antenna solid angle, and thus its directivity. Corrections must be applied for near-field effects, diffraction at the screen aperture, partial resolution of the screen aperture by the main lobe of the test antenna pattern, and ohmic losses. A comparison of black disk measurements using a large conical horn at 86 GHz with theoretical calculations confirms the accuracy of this gain calibration technique.     

Substrate Integrated Waveguide Corrugated Horn Antenna

Wireless Personal Communications - In this paper, a substrate integrated waveguide (SIW) H-plane horn antenna is proposed. We first optimize the antenna in size to obtain the maximum gain. The SIW...     

一种基于SIW技术的喇叭天线

设计了一种新型微带天线。天线印制板为基片集成波导结构,天线前端用金属过孔形成喇叭状,从而构成一种微带H面波导喇叭,通过微带线--波导转换结构进行馈电,在辐射主方向具有较高的增益。该天线集合了传统微带天线低剖面以及H面波导喇叭的集束、高增益的特性,最后应用Ansoft HFSS进行了设计和仿真,验证了设计的正确性。     

Octagonal DGS based dual polarised ring-shaped antenna for MIMO communications

In this article, a dual polarised Microstrip patch antenna is proposed for 2*2 MIMO communications. The proposed antenna is suitable for GSM/DCS-1800 and LTE-1900 bands as diversity and multiple-input multiple-output (MIMO) antenna. Different from conventional MIMO antennas, the radiating aperture is shared among the radiators, which greatly reduces the overall size of the MIMO antenna system. An isolation enhancement of 30 dB between the input ports is achieved by integrating cross-connected octagonal shaped Defected Ground Structure to the ground plane. Furthermore, the Multi-antenna system performance metrics such as Envelope Correlation Co-efficient, diversity gain and Mean Effective Gain, and Total Active Reflection Co-efficient are also computed. The Proposed antenna shows a gain of 3.63 dBi at 1950 MHz. The simulated and measured results demonstrate that the proposed antenna has good impedance matching, isolation and dual polarisation characteristics. From the performance metrics, the proposed antenna performs well in multipath environment.     

Constant Impedance TEM Horn Antenna: Aperture and Characteristic Impedance’s Impacts on Axial Electric Field

TEM horn antenna with constant characteristic impedance (CCI TEM horn antenna) is a widely used ultra-wideband (UWB) antenna. Considering the peak-to-peak value of the axial electric field (V_pp), how to design such antenna’s characteristic impedance (Z _c) has not been involved in previous research. The relationship between V_pp and antenna aperture as well as characteristic impedance is numerical analyzed. The simulation and experimental results show that the optimal aperture is existed to maximize V_pp when the antenna’s length is fixed at the axis. More over, V_pp of the antenna with optimal aperture reaches the maximum value when the characteristic impedance is 280 ohm.     

A 60-GHz Wideband Slot Antenna Based on Substrate Integrated Waveguide Cavity

This paper proposes a new wideband W-band substrate integrated waveguide (SIW) cavity-backed slot (CBS) antenna. The SIW cavity suppresses the backward radiation and ensures this antenna have a very low profile (only about 4% of the operating wavelength). Several techniques, such as slot resonator with semicircular end, quarter-wavelength microstrip resonator, are introduced to improve impedance matching. The studied results demonstrate that this antenna has wide operating bandwidth in 54.3–67 GHz (about 20.9% of the fractional bandwidth), unidirectional radiation pattern and good linear polarization characteristic. These properties are very suitable for RF front-end system-on-package (SoP) design in millimeter wave wireless communication systems.     

E波段宽带高增益透射阵天线设计

设计了一款E 波段高增益天线,该天线由基片集成波导缝隙天线和透射阵组成。为实现足够的相位补 偿范围,设计了多种贴片结构单元。该透射阵共有289 个单元,口径尺寸为33. 065 mm × 33. 065 mm,该天线的焦径比 为0. 45。实测结果表明,加载透射阵后,SIW 缝隙天线的增益提高了14. 63 dB,在74. 23 GHz 增益达到23. 28 dBi,口径 效率为24. 23%,3 dB 增益带宽为10. 83%。     

Low-profile ultra-wideband inverted-hat monopole antenna for 50 MHz?2 GHz operation

A compact low-profile UWB monopole antenna is proposed to operate from 50 MHz up to 2 GHz. The developed double-ellipse inverted-hat antenna (IHA) is 15 inches in aperture, 6 inches tall, and achieves 215 dBi gain at 75 MHz (when it is λ/10 in aperture size) in the presence of a finite 21 inch diameter ground plane, with the corresponding frequency being 50 MHz for an infinite ground plane. Calculated and measured gain data are given with reasonable agreement. The tripleellipse IHA is investigated to resolve impedance matching issues at higher frequencies. Gain performance against antenna height and aperture are also studied. The proposed antenna is especially suited for small unmanned aerial vehicles.     

Enhanced‐Gain Planar Substrate‐Integrated Waveguide Cavity‐Backed Slot Antenna with Rectangular Slot Window on Superstrate

A novel substrate‐integrated waveguide (SIW) cavity‐backed slot antenna is proposed in this study to achieve enhanced‐gain performance. The peak gain is remarkably improved with the use of an SIW cavity and metallic superstrate. The superstrate comprises a single rectangular slot window and two half‐wavelength patches. The gain can be enhanced by combining the in‐phase radiating fields. Further, the 10 dB bandwidth of the proposed antenna ranges from 2.32 GHz to 2.49 GHz, which covers the wireless local area network band. The measured peak gain is 9.44 dBi at 2.42 GHz.     

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.     

New exponential TEM horn antenna with binomial impedance taper

In this paper a new ultra wide band exponential transverse electro-magnetic (TEM) horn antenna with binomial impedance taper is presented. The binomial distribution is used for the impedance taper along the length of the proposed antenna. Using binomial distribution for the impedance taper causes the antenna to have minimum VSWR and flat gain in a wide frequency band. The proposed antenna was manufactured and its performance was compared with the antennas of the same size with exponential, Klopfenstein and triangular impedance tapers. Measurements show that the antenna has VSWR less than 2 in the frequency band from 3 to 15 GHz and less than 2.5 from 2 to 16.3 GHz. Having very good directional pattern and flat gain in a wide frequency band are significant characteristics of this new proposed antenna.     

High‐Performance Dual‐Circularly Polarized Reflector Antenna Feed

This paper presents a high‐performance dual‐circularly polarized feed employing a dielectric‐filled circular waveguide. Novel features are incorporated in the proposed feed, such as a dielectric rod radiator for high gain and good impedance matching; dual quarter‐wave chokes for low axial ratio over wide angles and for low back radiation; an integrated septum polarizer; and two end‐launch‐type coaxial‐to‐waveguide transitions. The proposed feed shows excellent performance at 5.0 GHz to 5.2 GHz.     

一种X波段波导缝隙天线的设计与仿真

给出了波导缝隙天线设计步骤,设计一种X波段波导缝隙天线,计算了天线口径、波导数量、缝隙的单元数量、宽度、位置等参数,设计半高波导宽臂耦合谐振缝魔T和差器,在此基础上完成了天线设计。仿真结果表明,当中心频率为12 GHz时,和波束增益为28.9 dB,第一副瓣电平为-22.2 dB,所设计的天线形式可获得较好的和、差波束方向图、电压驻波比和增益等参数。