Conventional Horn Research Articles

A novel flat lens horn antenna designed based on zero refraction principle of metamaterials

In this paper, a horn antenna filled with a metamaterial structure as lens inner the aperture is presented. Unlike conventional curve lenses, the lens is designed in the present work using a fully flat structure, which results in a great improvement for the directivity of the horn antenna based on the zero refraction characteristics of the metamaterial. In this structure, a periodic-structure metamaterial with three-layer metal grids is designed using the CST Microwave Studio for optimization and its zero refraction property is validated. For the characterization of the antenna, the electric-field distribution in radiation area, reflection parameter (S11), gain and radiation pattern are calculated. The results show that the gain of a wide flare angle horn antenna is enhanced with over 2 dB between 16.10–17.30 GHz after the metamaterial is utilized. Therefore, the metamaterial lens horn structure results in a miniaturized antenna design approach compared to the optimum conventional horn of the same aperture size and gain in the interested frequency band.

Multimode horn with optimum gain within circular area

AbstractIn this paper, a multimode horn efficiently illuminating the entire circular area is proposed. In comparison with the conventional dual mode horn with a pencil beam, the minimum gain within the covered area is higher by more than 1 dB. In the horn design, the mode excitation coefficients are derived from the universal pattern maximizing the gain in an arbitrary direction. By comparing this result with the optimum gain derived from the quadratic programming method, the effect of beam shaping is evaluated. The validity of the present method is verified by numerical analysis and by the measured radiation pattern of a curved flare multimode horn fabricated for trial in the X band. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(2): 12–21, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20246

Strong microwave second order rejection band in opal-like structures

The electromagnetic-transmission properties of opal-like structures made of glass marbles has been measured. All the cases show strongly rejected bands at frequencies corresponding to a Bragg 2nd-order of diffraction. The results show good agreement with appropriate simulations. Moreover, the structure presents a lens effect when placed properly at the output of a conventional horn antenna. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 472–475, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21204

High performance compact corrugated horn

The paper describes a new type of compact corrugated horn in which an unwanted higher order mode is cancelled at mid-band yielding a performance compatible with a conventional horn three times its length. Simple design equations are presented which enable a fast optimisation routine to be used in order to determine key parameters. Favourable comparison is made between measurements and predictions obtained using a well tried modal matching method.

VERY LONG BASELINE NEUTRINO OSCILLATION EXPERIMENTS FOR PRECISE MEASUREMENTS OF OSCILLATION PARAMETERS AND SEARCH FOR CP VIOLATION

We analyze the prospects of a feasible, very long baseline neutrino oscillation experiment consisting of a conventional horn produced low energy wide band beam and a detector of 500 kT fiducial mass with modest requirements on event recognition and resolution. Such an experiment is intended primarily to measure CP invariance parameters in the neutrino sector. We analyze the sensitivity of such an experiment. The conclusion is that it will allow determination of the CP parameter δCP, if the currently unknown mixing parameter sin 22θ13 ≥ 0.01, a value about 10 times lower than the present experimental upper limit. Such an experiment has great potential for precise measurements of all parameters in the neutrino mixing matrix including [Formula: see text], sin 22θ23, [Formula: see text], and the mass ordering of neutrinos through the observation of the matter effect in the νμ → νe appearance channel.

Destruction of phenol using sonochemical reactors: scale up aspects and comparison of novel configuration with conventional reactors

Acoustic cavitation is known to produce conditions extremely suitable for the destruction of pollutants but the industrial use is hampered by the lack of suitable scale-up/design strategies and lack of studies at pilot scale of operation. In the present work, the efficacy of acoustic cavitation for the destruction of phenol has been investigated using a novel triple frequency flow cell with a maximum capacity of 7.5 l. The results obtained have been compared with the conventional laboratory scale ultrasonic horn, which is most commonly used for the applications based on acoustic cavitation and another side entering sonochemical reactor with capacity of 400 ml again based on irradiation with single transducer at frequencies similar to the conventional horn. In the novel sonochemical reactor, the effect of frequency of irradiation on the rates of degradation has also been investigated. Some process intensification studies have also been carried out using surface cavitation in the large-scale reactor as well as the ultrasonic horn with an aim of increasing the rates of degradation.

Very long baseline neutrino oscillation experiments for precise measurements of mixing parameters andCPviolating effects

We analyze the prospects of a feasible, Brookhaven National Laboratory based, very long baseline neutrino oscillation experiment consisting of a conventional horn produced low energy wideband beam and a detector of 500 kton fiducial mass with modest requirements on event recognition and resolution. Such an experiment is intended primarily to determine $\mathrm{CP}$ violating effects in the neutrino sector for 3-generation mixing. We analyze the sensitivity of such an experiment. We conclude that this experiment will allow determination of the $\mathrm{CP}$ phase ${\ensuremath{\delta}}_{\mathrm{CP}}$ and the currently unknown mixing parameter ${\ensuremath{\theta}}_{13},$ if ${\mathrm{sin}}^{2}2{\ensuremath{\theta}}_{13}>~0.01,$ a value $\ensuremath{\sim}15$ times lower than the present experimental upper limit. In addition to ${\ensuremath{\theta}}_{13}$ and ${\ensuremath{\delta}}_{\mathrm{CP}},$ the experiment has great potential for precise measurements of most other parameters in the neutrino mixing matrix including $\ensuremath{\Delta}{m}_{32}^{2},$ ${\mathrm{sin}}^{2}2{\ensuremath{\theta}}_{23},$ $\ensuremath{\Delta}{m}_{21}^{2}\ifmmode\times\else\texttimes\fi{}\mathrm{sin}2{\ensuremath{\theta}}_{12},$ and the mass ordering of neutrinos through the observation of the matter effect in the ${\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{e}$ appearance channel.

Advanced process characterization for 125 kHz wire bonder ultrasonic transducers

A high frequency ultrasonic transducer for wire bonding is conceived, designed, prototyped, tested and industrially produced. The influence of each feature of the ultrasonic transducer design, such as constituent material, amplifier geometry, mounting flange, capillary fixing, on the wire bonding process results is clearly identified and carefully analyzed through thorough process tests. The assembly and aging characteristics of the transducers are measured and the scattering of the vibration properties in the mass production is statistically quantified by laser interferometer measurements and compared with that of conventional horns. The transducer is mounted on the wire bonder with a flange whose special geometry is calculated by means of FEM simulations and patented. This flange allows the mechanical stiffness of the coupling transducer-wire bonder to be dramatically increased and the parasitic mechanical dynamical vibrations at the horn tip to be significantly reduced. Process tests show that the reduction in mechanical vibrations obtained in this way allows a wire bonder scarcely capable normally to attain the 80 /spl mu/m fine pitch process, to perform easily the 60 /spl mu/m fine pitch process. A beneficial impact of the mechanical coupling horn-wire bonder on the process performance is ascertained. The use of titanium as horn material, characterized by a low thermal expansion coefficient, is proven by process tests to be effective in improving the placement accuracy of the wire bonder. The high vibration frequency of the transducer (125 kHz) is proven by process tests to be effective in improving the ball roundness and the fine pitch wire bonding capabilities of the wire bonder and in decreasing the minimum wire bonding temperature and the applied bond force. The new approach to characterize the process performance of new ultrasonic transducer designs is of general importance for wire bonding technology.

Transmit array of transistor amplifiers illuminated by a patch array in the reactive near-field region

In this paper, a small transmit array of transistor amplifiers illuminated by a passive array of microstrip patches in the reactive near-field region is investigated as a power-combining structure. The two cases considered are when the transmit array radiates in a free space and when a passive array similar to the one used for illumination collects the radiated power. A comparison of the performance of the proposed structure against the alternative one, which uses a conventional horn antenna as a power-launching/receiving device, is also presented.

GAUSSIAN PROFILED HORN ANTENNA FOR HISPASAT 1C SATELLITE

In this paper, the design and the measurements of a Gaussian profiled horn antenna for the 11.7-12.2 GHz frequency band for the HISPASAT 1C satellite are presented. The study shows the possibility of improving the electromagnetic and physical features of conventional horn antennas by using Gaussian techniques.

Characteristics and Strength of Friction Welded Simple Round Bar Horn.

The authors developed a new type of horn named round bar hornwhich is based on a different magnification principle from a conventional one. The horn is constructed by connecting simple round bars of different specific acoustic impedance, which gives uniform cross section along its axis. However, two different materials must be joined firmly to endure any vibration stress for practical applications. In this paper, we have attemped to use friction-welded joints consisting of SUS 304 stainless steel and A6061 aluminum alloy as the simple round bar horn. The characteristics of the input-output displacement amplitude, of the elevated temperature and of the frequency are investigated experimentally on the friction-welded simple round bar horn and on the conventional horns of step and exponential type, consisting of SUS 304 and A6061 respectively. Furthermore, ultrasonic fatigue tests have been performed on the friction-welded simple round bar horns and A6061 monometallic bars. The results shows promising possibilities for this new type of horn.

Performance of two single‐layer frequency‐selective surfaces as spatial filters

AbstractTwo single‐layer FSSs are presented as radiation filters in conjunction with a conventional horn antenna. The amplitude of the transmitted wave to the variation of the incidence angle is studied with a view to designing a spatial filter array. It is demonstrated that these single‐layer arrays act as spatial filters, following a simple design of a regular plurality of slotted elements. © 1993 John Wiley & sons, Inc.

Circularly Polarized Antenna for Transmitting Application

Broadband Circularly Polarized Diagonal Horn Antennas, capable of high power handling working over frequency 2.4 GHz through 12.4 GHz have been designed and developed. Low loss, high strength radome has been used to protect the antennas. The diagonal horn possesses almost perfect circular symmetry beam; thus resulting in low axial ratio off the antenna axis also. This antenna has very low side lobe in principal planes compared to conventional pyramidal horn of square cross section.The antenna is having directional coverage and can be used for high power transmitting application. Experimental results are presented. This type of antenna is ideally suited for shipborne, vehicle mounted and airborne applications.

Pseudo-Boolean valued prolog

A generalization of conventional Horn clause logic programming is proposed in which the space of truth values is a pseudo-Boolean or Heyting algebra, whose members may be thought of as evidences for propositions. A minimal model and an operational semantics is presented, and their equivalence is proved, thus generalizing the classic work of Van Emden and Kowalski.

Near-axis cross-polarization improvement of centre-fed parabolic antennas by partial shaping of the aperture distribution

An attempt to obtain a near-axis cross-polarization suppression of a parabolic reflector antenna has been made with the knowledge that a π-radian phase-difference dielectric plate rotates the polarization of the incident electric field. The antenna used was illuminated at the focus by a conventional simple-structure TE-11 mode feed horn. This was facilitated by mounting dielectric plates on portions of the reflector aperture and then by rotating the principal electric field opposite to the cross-polarized field. Numerical results show that cross-polarization within a − 10 dB angle of the principal beam is remarkably (more than 10 dB) suppressed below − 40 dB if the principal polarization field is properly rotated. Measured results at f = 12.15 GHz, with and without the dielectrics, are presented in this paper for comparison.

Acoustical signal apparatus

First Page

Radiation from a wide-angle conical horn with a homogeneous dielectric sphere in front of its aperture

The effects of placing a homogeneous dielectric sphere in front of the aperture of a wide-angle conical horn are studied both theoretically and experimentally. The theoretical formulation of the ratiation characteristics of the device is made on the basis of scattering of electromagnetic waves by a dielectric sphere. The calculations based on this formulation show overall agreement with the experimental radiation pattern and directivity measurements. It is concluded that the dielectric sphere mounted conical horns will have directiveities in excess of that obtained with a conventional conical horn of the same dimensions, and also that the device can be used as a variable beam feed for parabolidal reflectors.

Pattern analysis of corrugated horn antennas

The corrugated horn has been established as an antenna with low sidelobes and backlobes, rotationally symmetric patterns (for square pyramidal and conical horn shapes), and broad-band performance [1]-[9]. These properties make this horn useful for many applications. Previous studies have used conventional aperture integration techniques to evaluate the patterns of the corrugated horn. In general, the near axis <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</tex> -plane radiation pattern of a pyramidal corrugated horn may be adequately predicted from standard analysis established for the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</tex> -plane patterns of conventional horn geometries [3]. This method, however, fails to predict the far-out sidelobe and backlobe radiation levels. The work presented here uses a knowledge of the aperture fields to predict the pattern using aperture integration and diffraction theory. The assumptions made concerning the aperture fields were verified by probing the internal fields and aperture fields of an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</tex> band corrugated horn. The results of this field probing are contained in the Appendix. The method of solution used in this paper parallels that used in previous publications [10]-[12]. Specifically, the pattern in the main beam region is computed using conventional aperture integration procedures, the contribution of the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</tex> -plane edges is found using a slope diffraction analysis, and the contribution of the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</tex> -plane edges is found by use of duality.

Conical-reflector antennas

The mechanical advantages of a singly curved conical reflector are demonstrated by the experimental test of a furlable 1.83 m conical-Gregorian antenna at 16.33 GHz. The measured gain of 47.5 dB corresponds to a net efficiency of over 57 percent. A ray-optics analysis of conical-reflector antennas is presented, and data useful in the design of conical antennas is given. The conical-Gregorian antenna, in which a subreflector is used in conjunction with a conventional horn feed, is considered in detail. A physical-optics analysis of the conical-Gregorian antenna is used to investigate diffraction and other effects, and to analytically confirm the high performance of the antenna. It is concluded that conical antennas are a valuable addition to available antenna-design concepts.

Shaped beam antenna for Earth coverage from a stabilized satellite

The feasibility and practicality of achieving improved performance from a stabilized antenna on a synchronous satellite by shaping the beam for optimum earth coverage is shown. Due to the difference in range and atmospheric attenuation from a synchronous satellite to various points on the earth, a conventional beam with maximum gain toward the center of the earth is inefficient because it has the highest gain where the least gain is required. Since the paths tangential to the earth are longest and since they traverse through more atmosphere, the antenna gain should be highest in this region and decrease to a minimum for the path normal to the earth (see Fig. 1). The flat portions at the edge of the pattern allows for stabilization errors of the satellite. The ideal pattern has been calculated to give equal effective signal (including noise due to atmospheric attenuation and assumed preamplifier noise figures of the ground terminal and satellite) over the entire portion of the earth covered by the antenna beam. The ideal pattern is rotationally symmetrical and has the capability of dual orthogonal polarization. A relatively simple low-loss antenna that gives a good approximation to the ideal pattern is described. The antenna is a nine-horn array consisting of a large central horn surrounded by a ring of eight smaller horns. The central horn is multimoded to provide rotational symmetry and polarization purity. An optimum power division and relative phasing between the central and outer horns is made to give a pattern that closely approximates the ideal. Both theoretical and measured data are presented. Measured results confirm the beam shaping, rotational symmetry, polarization purity improved gain, and broad bandwidth expected from the array. A gain improvement of more than 2 dB over a well-designed conventional horn antenna has been demonstrated.