Conical Antenna Research Articles

Multi-band conical and inverted conical printed quadrifilar helical antennas with compact feed networks

Comparison between radiation patterns of quadrifilar helical antennas with three shapes of cylindrical, conical and inverted conical is provided in this paper. Multi-folded printed lines are used as the arms of quadrifilar helical antennas and the heights of them with their supports are fixed at 35cm to make a valid comparison. These antennas have multiple resonance frequencies and they can be used for multiband applications. Radiation patterns of the three shapes are compared at three resonance frequencies, 435MHz, 620MHz and 755MHz. It is indicated that the conical antenna has a wider beam-width and the inverted conical antenna has higher gain at broadside. In addition, three compact feed networks based on miniaturized single layer Wilkinson power dividers for three frequency bands of the antennas are designed and their parameters are reported. Furthermore, the conical antenna and the feed networks are fabricated and simulation results are validated by the measurement results.

A Conformal Conical Archimedean Spiral Antenna for UWB Communications

In this paper, a wide-band miniaturized Conformal conical Archimedean spiral (CCARS) antenna is proposed for Ultra wideband (UWB) communications. The CCARS antenna utilizes the vertical space instead of horizontal space significantly saving the antenna installation space. We investigate the transformation from Planar Archimedean spiral (PARS) antenna to the CCARS antenna and the antenna miniaturization technique. Due to the using of flexible dielectric substrate, the PARS antenna can be bent freely, which assures the transformation from the PARS antenna to the CCARS antenna. To realize antenna miniaturization, zigzag shape arms are applied to the PARS antenna. Moreover, the CCARS antenna has good unidirectional radiation property that avoids the using of traditional absorber-loaded back cavity. The measured results of antenna prototype indicate that the Voltage standing wave ratio (VSWR) is below 2 over the frequency range from 1.3GHz to 9GHz. The antenna gain is higher than 3.4dBi and the Front to back (F/B) ratio is better than 20dB from 2GHz to 7GHz. In addition, good radiation patterns and broad 3dB beam width are also available for the CCARS antenna.

Development of nanosecond rise time E-field sensor based on asymptotic conical antenna

In order to measure the electric field of electromagnetic pulse(EMP) with nanosecond rise time, a kind of broadband E-field sensor based on asymptotic conical antenna is proposed. The performance of the antenna is verified by modeling and simulation. An optical transmitter is designed to realize the electro-optical conversion and a fiber is used to transmit the signal. The output voltage of the sensor is integrated by Matlab. The performance of the sensor is tested by experiment. Research results show that this kind of measurement system has the characteristic of small size, good linearity, high noise immunity and wide-band response and it can be used to measure the E-field of EMP with nanosecond rise time. The development of the E-field sensor is of great significance for the measurement of EMP and further research on the characteristics and protection of EMP.

The Research of DOA Estimation Algorithms in the Conformal Array Antenna

To the conformal array antennas, the conventional DOA estimation algorithms will be affected by the Rayleigh limit. While, the MUSIC algorithm can solve this problem, it fully utilizes the orthogonality of noise subspace and signal subspace. It can achieve the DOA estimation through the spectrum peak search. The MUSIC algorithm is analyzed. Based on the cylindrical and conical array antenna, the algorithms are simulated. The simulation results show that the array arrangement mode can exert an important influence on the DOA estimation.

High Gain Conical Beam Antenna Array Exploiting Grating Lobes

The alternative solution is presented for single- and multi-ring arrays with a high-gain and wide elevation coverage conical beam. Effects of ring radii, number of elements, beam switching and multi-ring operation are analyzed using array theory. Gain enhancement at the large flare angle is obtained by using grating lobes of the array factor with conical pattern elements. The switching technology is employed to improve pattern ripple in azimuthal plane and to exploit the grating lobes for achieving high gain. Excitations of all the elements are in phase. A prototype of a single-ring array with 13 elements has been fabricated and measured. Three sub-arrays each composed of four elements are arranged on the ring and the other single element is located at the center. Measured results show that elevation beam coverage is from 20° to 55° and the maximum radiation gain is 9 dBi at 48° elevation at 12.5 GHz.

指数テーパ線路型コニカルモノポールアンテナのリターンロスに関する実験的検討

Exponential tapered line type conical monopole antenna is proposed as a radiator of electromagnetic wave due to electrostatic discharge (ESD). The electromagnetic wave radiated by discharge such as ESD is broadband and influenced by lead lines connected to discharge electrodes. Therefore, the broadband antenna, which can lay on the electrodes to the antenna input and withstand the high voltage, is required instead of lead lines. The proposed antenna is the conical monopole antenna having an exponential tapered line structure. The characteristic impedance of the antenna changes from 50Ω to the free space impedance according to exponential function. The return loss and input impedance of the conical monopole antenna were measured by a network analyzer in the frequency range from 300kHz to 9GHz. As a result of experiment, the return loss was less then -20dB and the input impedance was 50Ω in frequency range from 1.6GHz to 9GHz. The results of the experiment are compared with the linear tapered line type monopole antenna that the characteristic impedance changes from 50Ω to the free space impedance linearly. The return loss of the conical monopole antenna was lower than that of the linear tapered line type monopole antenna.

An UWB Conical Monopole Antenna for Multiservice Wireless Applications

A novel formation of a conical monopole antenna is presented for ultra-wideband (UWB) and multiple other wireless services. The proposed antenna design is compatible with many wireless standards, including Wi-Fi (2.4 GHz), Bluetooth (v1.0-v4.0), WiMAX ( ~ 2.5-5.5 GHz) and Bluetooth 4.0 or Wireless USB (3.1-10.6 GHz). It is also has a suitable frequency response for close range radar and satellite communication in the X band ( ~ 8-12 GHz) and Ku band ( ~ 12-18 GHz) applications. The proposed design is approximately 0.24λ in length with respect to the lowest frequency boundary at the 2.4 GHz Wi-Fi band. The structure consists of two mechanical parts, which are the cone and a cylindrical block (disc). The proposed conical monopole antenna displays a fractional bandwidth of 8.3:1 and a simulated maximum efficiency of over 95% across the whole frequency range. The radiation patterns are largely omnidirectional. Furthermore, it displays a useful level of gain across the impedance bandwidth and the time domain response indicates promising performance for radar and impulse radio. In short, the proposed conical monopole offers ultra-broad bandwidth with omnidirectional radiation patterns, in a reasonably small and easy to construct structure.

A NEW CONICAL BAND-REJECT UWB ANTENNA WITH UNIFORM REJECTION AND STABLE OMNIDIRECTIONAL BEHAVIOR

This paper introduces a new volumetric conical notch-band antenna. Structure of this antenna is in contrast with planar and printed band rejection antennas currently existing in almost all of the literatures. The radiation pattern of the proposed antenna is symmetrical and stable against frequency variation, while planar and printed antenna types suffer from high variation of their radiation pattern with frequency, and consequently asymmetric and unstable omnidirectional behavior. The frequency band of the antenna is notched with two slots implemented on the antenna structure. Uniform various frequency band rejections are achieved by changing the slots dimensions and position. Both measured and simulation results of manufactured antenna show the frequency bandwidth of the antenna is from 3 to 4.9GHz and from 6.2 to 11GHz with reflection coefficient less than −10 dB. Moreover, the antenna notches the frequency band from 4.9 to 6.2GHz with nearly uniform reflection coefficient level of approximately −3 dB. Stable radiation pattern and proper range of frequency band rejection make the designed antenna an appropriate candidate for the use in UWB and indoor communication systems.

Substrate Integrated Waveguide Leaky-Wave Antenna Conforming to Conical Shape Surface

A conical conformal leaky-wave antenna based on substrate integrated waveguide (SIW) technology is proposed and demonstrated in this paper. This antenna conforms to a conical shape surface with the angle of 40°. It has a narrow beam that scans from 80° to 97° with varying frequency (34 GHz~37 GHz). Both conformal and nonconformal antennas are fabricated through the standard PCB process. Their performances are compared within the desired frequency.

A Bottom Fed Deployable Conical Log Spiral Antenna Design for CubeSat

A conical log spiral antenna is presented with a new feeding scheme. This antenna is proposed for deployment on a CubeSat platform where the new feeding technique allows for easier antenna deployment. The antenna is composed of two arms that are wrapped around each other in a log-periodic manner. It is designed on top of a ground plane allowing its bottom feeding property. The feeding network is composed of quarter-wavelengths transmission lines connected to a planar balun. The feeding network along with the balun provides the antenna with the appropriate impedance matching and phase shift between the two arms. The antenna is fabricated and tested. The measurement and simulation results show good agreement.

基于渐进圆锥天线的ns前沿电磁脉冲电场传感器

基于渐进圆锥天线的ns前沿电磁脉冲电场传感器

동축 프로브 급전구조에 대한 FDTD 전원 모델들의 상호 관계에 관한 비교 연구

RF 및 마이크로파 대역에서 동축 프로브 급전구조에 대한 효율적인 유한 차분 시간 영역(FDTD: Finite-Difference Time-Domain) 해석을 위한 등가 전원 모델링 기법들의 상호 관계를 연구하였다. 기존에는 델타 갭(delta-gap) 또는 자기 프릴(magnetic-frill) 개념을 FDTD에 도입한 등가 전원 모델들이 여러 연구진에 의해서 개발되었다. 이러한 등가 전원 모델들의 FDTD 구현 방법과 모의 계산의 정확성은 서로 조금 다르다는 정도로만 잘 알려져 있었다. 본 논문에서는 준정적 근사(quasi-static approximation)하에서 동축-프로브 급전 구조에 대한 FDTD 등가 전원 모델들의 상호 관계를 제시하였다. FDTD 등가 전원 모델들의 적용방법에 따라 동축 급전된 원추형 모노폴 안테나의 시간영역과 주파수영역 응답을 수치계산하였다. 또한, FDTD 모의계산의 정확성과 효율성에 대한 비교 결과를 제시하였다. For an efficient finite-difference time-domain(FDTD) analysis of coaxial-probe feeding structures in radio frequency(RF) and microwave bands, an interrelation between equivalent source modeling techniques is investigated. In existing literature, equivalent source models with delta-gap or magnetic-frill concepts have been developed by many researchers. It is well known that FDTD implementation and computational accuracy of these source models are slightly different. In this paper, the interrelation between FDTD equivalent source models for coaxial feeding structures under the quasi-static approximation(QSA) is presented. As a function of FDTD equivalent source models, time-domain and frequency-domain responses of a coaxial-probe fed conical monopole antenna are calculated numerically. And comparison results of computational accuracy and efficiency are provided.

Design of High-Directivity Compact-Size Conical Horn Lens Antenna

The design of lightweight, compact-size, and high-directivity conical horn lens antenna that covers both 71-76 and 81-86 GHz bands is presented in this letter. The conventional conical moderate-gain horn antenna is integrated with a planar inhomogeneous dielectric flat transmit-array lens having diameter of 35 mm and thickness of 6.35 mm by covering its aperture. The transmit-array lens is designed based on the perforating dielectric technique that is based on the drilling of numerous holes of variable diameters through a dielectric host material. The unit cell size is about λ0/2, which allows for easier fabrication. The proposed lens consists of eight concentric zones of same width of 2.32 mm and sharing the same host dielectric material. A directivity of 26.4 dBi, 9 dBi improvement, sidelobe level (SLL) of -15.7 dB at 74 GHz and directivity of 27 dBi, 9.9 dBi improvement, and SLL of -18.4 dB at 86 GHz were achieved. The proposed horn antenna is 44.46% shorter than the conventional horn antenna producing the same directivity, where the horn antenna length reduction is a result of using the proposed transmit-array lens.

Proposal of a Planar Directional UWB Antenna for Any Desired Operational Bandwidth

A novel planar directional UWB antenna is proposed. The antenna design evolves from an oblique elliptic cone antenna by applying the planar-solid correspondence to two axes. Through a simple equation, this antenna can be designed, to operate at a specific lower cutoff frequency with a bandwidth larger than 10 GHz for a reflection coefficient magnitude lower than −10 dB. This characteristic provides the antenna with a good versatility. The directional radiation pattern has an average gain of 6 dBi.

Wave Propagation Between Buried Antennas

Buried antennas can be used in a variety of applications. For surface communication, parameters such as the ground conductivity and the depth of the buried antenna affect the channel attenuation between the antennas. A buried conical antenna for surface communication was developed at Soreq NRC. The antenna is axis-symmetric with two metallic plates, where the upper plate is conical and the lower is a flat disc. The wave propagation from the buried antenna is studied using an axis-symmetric finite-difference time-domain approach. It was found that the energy is radiated from the buried antenna to above the ground, where it forms a spherical surface wave. Due to the wave propagating above the ground faster than below the ground, the penetration of the surface wave into the ground is shaped as a shock wakefield. This wakefield is absorbed into the ground due to the finite ground conductivity. The shock wavefront corresponds to the Cherenkov angle cos <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> (1/ε <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rg</sup> ), where ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rg</sub> is the ground relative dielectric permittivity. The channel attenuation from the buried antenna to a receiving antenna located either above or below the ground surface scales as 1/r <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> . Experimental demonstration was performed at 900 MHz . A good correlation was obtained for the channel attenuation between the experimental and simulation results, irrespective of whether the receiving antenna was located above or below the ground surface.

Design of Ka-Band Inset-Fed Conical Conformal Patch Antenna

Conical conformal microstrip patch antenna is very important in wireless communication and microwave instrument. In this paper, a Ka-band rectangular inset-fed microstrip patch antenna which conforms to a conical surface has been designed, the specific designed method and parameters were given. Then a conical conformal microstrip antenna is simulated by CST, the difference between planar antenna and conical conformal antenna has been discussed, and the effect of surface curvature on conical conformal antenna resonant frequency of has been analyzed.

Conical antenna design for the excitation of RTL chamber for cell experiments

In this article, a conical antenna fed by coaxial line fed for the excitation of the radial transmission line (RTL) chamber is designed and fabricated. This antenna is analyzed by the finite-difference time-domain (FDTD) method and the input impedance is simulated. An RTL chamber was used by the device for in vitro experiments. The designed antenna has advantages, such as ultra-broadband characteristic and omnidirectional radiation. The bandwidth of fabricated antenna has 630–2590 MHz at voltage standing wave ratio ≤ 2. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1558–1560, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27646

Stacked Conical Ring Dielectric Resonator Antenna Excited by a Monopole for Improved Ultrawide Bandwidth

Stacked conical ring dielectric resonator antennas (DRA) excited by an axi-symmetric coaxial monopole are investigated numerically and experimentally for improved bandwidth. The bandwidth improvement is due to an extra resonance which occurs near the frequency where the monopole height is about a full wavelength. We consider two cases of the hybrid antenna: one case in which the tips of both cones face up and a second case in which the top cone is inverted to form a “sand-glass” shaped DRA. Measured data were obtained to validate the results of simulations. The proposed hybrid antennas can easily offer a fractional impedance bandwidth up to 138% along with monopole type radiation pattern. The antennas have a relatively low peak gain around the extra resonance.

CONICAL BEAM WINDMILL-SHAPED ARRAY ANTENNA DESIGN BASED ON QUARTER-MODE SUBSTRATE INTEGRATED WAVEGUIDE

This paper presents a compact conical beam antenna based on quarter-mode substrate integrated waveguide (QMSIW). The antenna array is consisted of six isosceles right-angled triangle metallic patch printed on the upper side of the substrate in a windmill-shape and diagonal periodic metallic via holes drilled along the hypotenuse of the triangle patch. The planer structure exhibits conical beam radiation. The typical radiation is obtained at 5.2GHz with conical beam radiation pattern. The measured gain is about 5.36dBi and the radiation e-ciency is around 50%.

THE FINE-GRAINED PARALLEL MICRO-GENETIC ALGORITHM AND ITS APPLICATION TO BROADBAND CONICAL CORRUGATED-HORN ANTENNA

The flne-grained parallel micro-genetic algorithm (FGP- MGA) is developed to solve antenna design problems. The synthesis of uniformly exited unequally spaced array is presented. Comparison with the micro-genetic algorithm (MGA) has been carried out. It is seen that the FGPMGA signiflcantly outperforms MGA, in terms of both the convergence rate and exploration ability. The FGPMGA can also reduce the optimization time. Then the FGPMGA and the body of revolution flnite-difierence time-domain (BOR-FDTD) are combined to achieve an automated design process for conical corrugated-horn antenna. Numerical simulation results show that the horn antenna has good impedance matching (the VSWR is less than 1.5), stable beamwidth and gain, as well as good rotation symmetry patterns over the whole band 8»13GHz.