Conical Horn Research Articles

DESIGN OF A CONICAL HORN ANTENNA FOR ULTRA-WIDEBAND APPLICATIONS

Due to rapid development in wireless technologies, ultra-wideband antennas are becoming increasingly important nowadays to cover many bands of frequencies and to support different applications by using single antenna. This paper outlines the design of an ultra- wideband conical horn antenna, which covers the range of frequencies from 6GHz to 18GHz with high gain, i.e., 23dB. This antenna can be effectively used for satellite communication and terrestrial broadcasting.

Broadband polarization-adjustable antenna realized by waveguide circular polarizers.

A broadband polarization-adjustable antenna realized by two waveguide circular polarizers is proposed in this paper. The antenna consists of a rectangular-to-circular transition waveguide, two identically structured rectangular slot circular polarizers, and a conical horn, all connected in sequence. By rotating the two circular polarizers to specific angles, the antenna can switch among four polarization modes: horizontal polarization, vertical polarization, left-hand circular polarization, and right-hand circular polarization. The antenna polarization adjustment principle is thoroughly analyzed. Taking the X-band polarization-adjustable antenna as an example, simulation and optimization were performed, and a prototype was fabricated and measured. The antenna's reflection coefficient is below -18 dB across all polarization modes from 9.2 to 10GHz. In linear polarized modes, gains exceed 10.5 dBi. For circular polarized modes, the gains align with those of linear modes, with an axial ratio of less than 1 dB in the operating frequency band. The measured results are consistent with the simulation results, confirming its excellent polarization adjustment performance and potential for high power microwave applications.

The first results of the hydrogen cyanide (HCN) interferometer measuring experimental research apparatus for electromagnetic science (ERAES) for hypersonic vehicle plasma in near space.

The formation of a plasma sheath on the surface of spacecraft or satellites during high-speed atmospheric entry is a significant factor that affects communication and radar detection. Experimental research apparatus for electromagnetic science can simulate this plasma sheath and study the interaction mechanisms between electromagnetic waves and plasma sheaths. Electron density is a crucial parameter for this research. Therefore, in this paper, a HCN heterodyne interferometer has been designed to measure the electron densities of the device, which range from 1 × 109 to 3 × 1013cm-3 and the pressure ranges from 50 to 1500Pa. The light source is a HCN laser with a wavelength of 337 µm, which exhibits higher spatial resolution compared to microwave interferometers. The interferometer is configured as a Mach-Zehnder interferometer, which generates an intermediate frequency through the Doppler shift achieved by a rotating grating. The spatial and temporal resolution of the HCN interferometry reach ∼14mm and 100 µs, respectively. Antenna-coupled ALGaN/GaN-HEMT detectors have been utilized, as they possess higher sensitivity-with a typical reduction factor responsivity of around 900 V/W-than VDI planar-diode Integrated Conical Horn Fundamental Mixers in HCN interferometry. Recently, the initial results of the HCN interferometer designed for ERAES have been obtained during an experimental campaign, demonstrating a phase resolution of up to 0.04π.

Applied methods for 3D modeling of radio engineering devices

The aim of the paper is to present applied methods for engineering 3D modeling of pyramidal and conical horn antennas, which can contribute to the implementation of experimental research, both in a simulation and in a physical environment. The practical results presented at each step of the model building process are represented by screenshots of the work screen showing the used toolbars from the Autodesk 123D Design software menu. This is done with a view to improving the quality of training in areas related to the study of radio engineering devices, such as telecommunications engineering and aerospace engineering, in which the design and manufacture of various types of antennas help to conduct independent empirical research by the trainees with the help of measuring equipment.

Performance analysis of circular polarization X-band microstrip patch antenna combined with conical horn

Performance analysis of circular polarization X-band microstrip patch antenna combined with conical horn

A Comprehensive Theory on Gain and Field of View of Conical Horn for Sensing Applications in the Optical and THz Ranges

A Comprehensive Theory on Gain and Field of View of Conical Horn for Sensing Applications in the Optical and THz Ranges

205–240 GHz free-space-to-fiber mode adapter with an 80% mode conversion efficiency

In this work, we propose an integrated terahertz mode adapter that couples broadband terahertz radiation from free-space to hollow-core fiber with a high mode conversion efficiency (Gaussian beam-to-TE01) of up to 80%. The adapter consists of a pyramidal horn antenna, a broadband mode converter, and a conical horn. The simulation results indicate that the TE01 mode in the hollow-core fiber can be efficiently excited by the terahertz mode adapter. The terahertz mode adapter successfully achieved a wide operating bandwidth of more than 15.7% ranging from 205 to 240 GHz in our simulation.

Harmonic Excitation Response of Standard Ultrasonic Horn Designs for Machining Nomex Honeycomb Core Composite

Ultrasonic horn plays a vital role in achieving vibration amplitude at tool end (VATE) by enhancing output displacement of piezoelectric ultrasonic transducer suitable for efficient machining of advanced composites. Higher vibration amplitude enhances ultrasonic machining quality, surface integrity and dimensional accuracy of Nomex honeycomb composite (NHC) while reducing cutting forces. Furthermore, low stress concentrations allow ultrasonic tool to have more safety factor and longevity. Ultrasonic horn is designed to enhance displacement amplitude of piezoelectric ultrasonic transducer and get optimum VATE while keeping stresses in acceptable limits to avoid failure at very high operating frequency of ultrasonic machining system. In this research, variety of standard ultrasonic horns (SUH) were designed with same length and end diameters; and were tested under similar operating conditions, using finite element method. The ultrasonic actuation of the horn exploits the first axial mode of horn vibration. Harmonic response analysis was carried out to determine axial modal frequencies (AMF), VATE, stresses, and factor of safety for performance evaluation. VATE attained by step horn was found to be greatest among all other SUHs for frequency ratio greater than one, but may be prone to early failure due to high stress concentrations. VATE achieved by third order Bezier, Gaussian, exponential, catenoidal, conical and second order Bezier horns were found less than that of step horn by 11.7 %, 16.6 %, 16.7 %, 17 %, 16.73 % and 18 % respectively. However, 44.2 %, 43.43 %, 42.5 %, 43.5 %, 42.8 % and 37.67 % reduction of stresses was achieved by Gaussian, exponential, catenoidal, conical, second and third order Bezier horns respectively. Outcomes of present work would be beneficial for designers, researchers, scientists, and manufacturers of ultrasonic machine tool to select appropriate SUH designs according to requirements.

Flat-topped Beams using Phase Compensation based on Low-profile Transmitarray

This paper proposes a method to add an additional phase compensation to conventional phased arrays to achieve flat-topped beam forming, which can convert the spherical waves emitted by common conical horn antennas into cylindrical flat-topped beams, at the same time, there is also a certain power enhancement. A centrosymmetric unit composed of four layers of F4B and metal patches is designed. By changing the value of the parameters, a 360∘ phase change can be achieved, and it has the advantages of small size and low-profile. To validate the design concept, a prototype of the transmitarray (TA) was designed, fabricated, and measured by calculating the phase distribution of the front. The measurement results show that the designed TA can achieve flat-topped beams at 5.2GHz, the maximum gain is 1.15dB higher than that of the horn antenna, and the flat-topped range is about ±10∘. The results are in good agreement with the simulation within the test range.

Long Range and Wide Field of View Thermal Detection Miniature System with a Conical Horn

Long Range and Wide Field of View Thermal Detection Miniature System with a Conical Horn

Design and Experimental Study of Longitudinal-Torsional Composite Ultrasonic Internal Grinding Horn.

Longitudinal-torsional composite ultrasonic vibration has been widely used in grinding. This paper aims to solve the problem that the resonance frequency deviates greatly from the theoretical design frequency and the vibration mode is poor when the horn is matched with a larger tool head. This paper presents how the longitudinal-torsional composite ultrasonic conical transition horn was designed and optimized by the transfer matrix theory and finite element simulation. For this purpose, the spiral groove parameters were optimized and selected by finite element simulation. Then, the modal analysis and transient dynamic analysis of the horn with grinding wheel were carried out to verify the correctness of the theoretical calculation. The impedance analysis and amplitude test of the horn with grinding wheel were carried out. The test results were in very good agreement with the theoretical and simulation results. Finally, the grinding experiment was carried out. The surface roughness of the workpiece in longitudinal-torsional ultrasonic vibration grinding was obviously reduced compared to that of ordinary grinding. All these obtained results demonstrate that the designed longitudinal-torsional composite ultrasonic horn has very good operational performance for practical applications.

Optimization of Pyramidal and Conical Horn Antennas Parameters to Operate with High Radiation Performances for 5G Communication Using CST and HFSS Techniques

Optimization of Pyramidal and Conical Horn Antennas Parameters to Operate with High Radiation Performances for 5G Communication Using CST and HFSS Techniques

Dual-Mode Conical Horn Antenna with 2-D Azimuthal Monopulse Pattern for Millimeter-Wave Applications.

In this paper, a novel concept of a three-dimensional full metal system including a Dual-Mode Converter (DMC) network integrated with a high-gain Conical Horn Antenna (CHA) is presented. This system is designed for 5G millimeter wave applications requiring monopulse operation at K-band (37.5-39 GHz). The DMC integrates two mode converters. They excite either the TE11cir or the TE01cir modes of the circular waveguide of the CHA. The input of the mode converters is the TE10rec mode of two independent WR-28 standard rectangular waveguide ports. By integrating the DMC with the CHA, the whole system, called a Dual-Mode Conical Horn Antenna (DM-CHA), is formed, radiating the sum (Σ) and difference (Δ) patterns associated to the monopulse operation. To adequately prevent the propagation of higher order modes and mode mutual coupling, this integration procedure is carefully designed and fabricated. To prove the performance of the design, the DMC network was fabricated using subtractive manufacturing by Computer Numerical Control (CNC) technology. The CHA was fabricated using additive manufacturing by Direct Metal Laser Sintering (DLMS) technology. Finally, the simulation and measurement results were exhaustively compared, including return loss, isolation, radiation pattern, and gain of the full DM-CHA structure. It is noteworthy that this system provided up to ±11° per beam in the angular of arrival detection to support the high data rate operation for 5G satellite communications in the millimeter-wave band.

Effect of electron number densities on the radio signal propagation in an inductively coupled plasma facility

Spacecraft entering a planetary atmosphere are surrounded by a plasma layer containing high levels of ionization, due to the extreme temperatures in the shock layer. The high electron number densities cause attenuation of the electromagnetic waves emitted by the on-board antennas, leading to communication blackout for several minutes. This work presents experimental measurements of signal propagation through an ionized plasma flow. The measurements are conducted at the VKI plasma wind tunnel (Plasmatron) using conical horn antennas transmitting in the Ka-band, between 33 and 40 GHz. Testing conditions at 15, 50 and 100 mbar, and powers between 100 and 600 kW cover a broad range of the testing envelope of the Plasmatron as well as a broad range of atmospheric entry conditions. The transmitting antenna is characterized at the UPC anechoic chamber, obtaining the radiation patterns, beamwidth, and gain at the boresight direction; and an optical ray tracing technique is used to describe the electromagnetic waves propagation in the plasma flowfield inside of the Plasmatron chamber. The signal propagation measurements show clear attenuation when the signal is propagating through the plasma, varying between 2 and 15 dB depending on the testing conditions. This attenuation increases with electron number densities, which are driven by the Plasmatron power and pressure settings. Preliminary evidence of Faraday rotation effects caused by the plasma is also observed.

A 3-D Printed Lightweight Miniaturized Dual-Band Dual-Polarized Feed Module for Advanced Millimeter-Wave and Microwave Shared-Aperture Wireless Backhaul System Applications

A 3-D-printed lightweight miniaturized dual-band dual-polarized feed module of wireless backhaul systems consisting of a dual-band air-filled waveguide orthomode transducer (OMT) and a shared-aperture conical horn radiator is investigated. The OMT operating in both Ku- and E-bands with a large frequency ratio is realized by combining the turnstile-junction-type and Bøifot-junction-type OMTs sharing a common-mode-composite coaxial port. A design method of the dual-band OMT considering the requirement for a self-supporting geometry in metallic 3-D printing is presented, so that its compact configuration that is difficult to fabricate by traditional milling technology can be fulfilled conveniently in a whole piece with the use of commercial 3-D printing facilities. A millimeter-wave horn with a small radiation aperture is embedded into a larger aperture of a microwave horn. A proper longitudinal offset between them is introduced to guarantee promising radiation characteristics of the shared-aperture scheme in the two bands. By connecting the OMT with the radiator, the proposed dual-band dual-polarized feed module with a weight of only 100 g is manufactured and measured. Excellent performance, involving the wide bandwidths of 46.7% and 31.2% at microwave and millimeter-wave frequencies, a high isolation of almost larger than 40 dB, a high radiation efficiency of about 90%, and stable dual-polarized radiation patterns with low cross polarizations, is confirmed experimentally. Benefitted from the geometric and operating merits, the feed module would be attractive for applications in advanced millimeter-wave and microwave shared-aperture wireless backhaul systems.

A horn-coupled millimetre-wave on-chip spectrometer based on lumped-element kinetic inductance detectors

Context. Millimetre-wave astronomy is an important tool for both general astrophysics studies and cosmology. A large number of unidentified sources are being detected by the large field-of-view continuum instruments operating on large telescopes. Aims. New smart focal planes are needed to bridge the gap between the large bandwidth continuum instruments operating on single-dish telescopes and high spectral and angular resolution interferometers (e.g. ALMA in Chile and NOEMA in France). The aim is to perform low to medium spectral resolution observations and select a lower number of potentially interesting sources (i.e. high-redshift galaxies) for further follow-up. Methods. We have designed, fabricated, and tested an innovative on-chip spectrometer sensitive in the 85–110 GHz range. It contains 16 channels, each of which covers a frequency band of about 0.2 GHz. A conical horn antenna coupled to a slot in the ground plane collects the radiation and guides it to a millimetre-wave microstrip transmission line placed on the other side of the mono-crystalline substrate. The millimetre-wave line is coupled to a filter-bank spectrometer. Each filter is capacitively coupled to a lumped-element kinetic inductance detector (LEKID). The microstrip configuration provides the benefit of low loss, due to the mono-crystalline substrate, and protects the LEKIDs from illumination by stray un-filtered light. Results. The prototype spectrometer exhibits a spectral resolution R = λ/Δλ ≈ 300. The optical noise equivalent power is in the low 10−16 W Hz−1/2 range for an incoming power of about 0.2 pW per channel. The device is polarisation-sensitive, with a cross-polarisation lower than 1% for the best channels.

COMPACT CORRUGATЕD HORN ANTENNA INITIAL DESIGN FOR MICROWAVE DIAGNOSTICS IN URAGAN-2M STELLARATOR

In this paper, a well-known design procedure is proposed for the design of wideband constant-beam width conical corrugated horn antennas, with minimum design and construction complexity. The inputs to the procedure are the operating frequency band, the required minimum beam width in the entire frequency band, and the frequency in which the maximum gain is desired to occur. Based on these values, the procedure gives a relatively good design with a relative bandwidth of up to 2.1:1. Based on the proposed procedure, a corrugated horn antenna with a constant beam width over the frequencies of 10 to 14 GHz was designed and simulated using commercial software. This paper presents initial design for the development of quasi-optical corrugated conical horn for reflectometry diagnostics for the Uragan-2M stellarator plasma experiments.

Conical Horn Antenna with High Gain and Circular Polarization for Sub-mm-Wave/Terahertz

Conical Horn Antenna with High Gain and Circular Polarization for Sub-mm-Wave/Terahertz

A millimetre-wave superconducting hyper-spectral device

Abstract Millimetre-wave observations represent an important tool for cosmology studies. The line intensity mapping technique has been proposed to map in three dimensions the specific intensity due to line (e.g. [C ii] and CO) emission, e.g. from the primordial galaxies, as a function of redshift. Hyper-spectral integrated devices have the potential to replace the current Fourier transform, or the planned Fabry–Perot-based instruments operating at millimetre and sub-millimetre wavelengths. The aim is to perform hyper-spectral mapping, with a spectral resolution R = λ/Δλ = 100–1000, over large, i.e. thousands of beams, instantaneous patches of the sky. The innovative integrated device that we have developed allows avoiding moving parts, complicated and/or dispersive optics, or tunable filters to be operated at cryogenic temperatures. The prototype hyper-spectral focal plane is sensitive in the 75- to 90-GHz range and contains 19 horns for 16 spectral-imaging channels, each selecting a frequency band of about 0.1 GHz. For each channel a conical horn antenna, coupled to a planar superconducting resonant absorber made of thin aluminium, collects the radiation. A capacitively coupled titanium–aluminium bi-layer Lumped Element Kinetic Inductance Detector is then in charge of dissipating and sensing the supercurrent established in the resonant absorber. The prototype is fabricated with only two photolithography steps over a commercial mono-crystalline sapphire substrate. It exhibits a spectral resolution R = λ/Δλ ≈ 800. The optical noise equivalent power of the best channels is in the observational relevant $4\cdot 10^{-17} W/\sqrt{Hz}$ range. The average sensitivity of all the channels is around $1\cdot 10^{-16} W/\sqrt{Hz}$. The device, as expected from three-dimensional simulations, is polarization-sensitive, paving the way to spectro-polarimetry measurements over very large instantaneous field of views.

Graded index all-dielectric lens antenna designed by phase manipulation and optical path rescaling

A rotationally symmetric all-dielectric lens antenna is designed by defining the phase function inside the dielectric directly via a closed-form series formula. The refractive index of the lens is modified using state-of-the-art optical path rescaling to keep the refractive index within practical values. The lens optimization is done using the genetic algorithm in MATLAB, where each case is evaluated by conducting linked ray tracing and full-wave electromagnetic simulation in COMSOL. A lens prototype is shown to provide a directivity enhancement of 5.1 dB compared to the optimal conical horn antenna, an improvement of 2 dB compared to the Luneburg lens, and an improvement of 3.8 dB compared to a reference graded index lens. All the examined cases shared a similar length of 5λ for the center frequency of 10 GHz. The prototype lens antenna has a maximum refractive index of 2.1, a reflection coefficient of −22 dB, and a side-lobe level of −25 dB at the center frequency of 10 GHz. The lens’ performance is consistent in the 9–11 GHz band supported by the standard circular waveguide. The results from a prototype with a discretized refractive index simulated in CST Studio Suite are in excellent agreement with the ones with a continuous refractive index profile simulated in COMSOL.