Conical Horn Antenna 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.

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.

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.

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 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.

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.

Very Compact Waveguide Orthomode Transducer in the K-Band for Broadband Communication Satellite Array Antennas

A very compact waveguide orthomode transducer (OMT) is described in this paper. The design is characterized with a twofold rotationally symmetric cross-section in the probing area, adapted from a side-coupling OMT design, simultaneously enabling low port-to-port coupling and high cross-polarization discrimination (XPD) over a fractional bandwidth of about 15-20%. Compared to previously reported compact waveguide OMTs, the proposed design is simpler, thus facilitating its manufacture at millimeter-wave frequencies. The concept is demonstrated with a design in the K-band for a broadband communication satellite downlink over the frequency band of 17.3-20.2 GHz. For test purposes, transitions to standard waveguide WR42 are included, and the OMT is assembled with a conical horn antenna. The measured reflection and coupling coefficients are below -19.5 dB and -22.9 dB, respectively, over the nominal bandwidth, and they are in good agreement with the simulation's results. The on-axis XPD, measured in an anechoic chamber, is better than 30 dB over the nominal bandwidth, which is also in line with simulations. The proposed waveguide OMT may be designed to fit in a lattice below one wavelength at the highest operating frequency, which is desirable for dual-polarized closely spaced array antennas in low and medium Earth orbit communication satellite systems. The simple mechanical design of the proposed OMT makes it particularly appealing for additive manufacturing techniques, as demonstrated with a variant of the design having folded single-mode waveguides, which preserves the RF properties of the original design.

Quasioptics for increasing the beam efficiency of wireless power transfer systems

The highest beam efficiency in a wireless power transfer (WPT) system that uses focusing components was 51%, using a approx {3},{textrm{m}} diameter reflector for a transfer distance of {7.62},{textrm{m}}. We have beaten that record, and present here a system that surpasses it by 25%. Using the quasioptical framework for reducing spillover losses in WPT, we present a double-reflector system that achieved a higher beam efficiency than the state-of-the-art. The transmitting and receiving antennas were 3D-printed conical smooth-walled horn antennas, specially designed for this purpose. The theoretical analysis enabled the design of a {5},{textrm{m}} system, whose energy focus location has been experimentally verified. Then, the complete system was experimented upon, enabling a high beam transfer efficiency of 63.75%. Additionally, the advantage of using quasioptics in radiative wireless power transfer applications is discussed, as well as the sensitivity of its systems. Finally, a comparison with the state-of-the-art is done by the proposal of new figures-of-merit, relating the systems’ physical dimensions and beam efficiency. This research is a paradigm shift by presenting a promising path for future WPT research through quasioptics, whose high efficiencies may enable commercial applications of this technology for solving power supply issues in our society.

Stable phase‐centre horn antenna using 3D printed dielectric rod for aperture efficiency improvement of space‐fed antennas

The design strategy to stabilise the phase centre (PC) of the conventional horn antenna using a shaped dielectric rod is presented for aperture efficiency improvement of space-fed antennas. In most practical horn antennas, PC location has significant variations with frequency leading to phase error loss and aperture efficiency reduction over the bandwidth of interest. To overcome this drawback, based on physical reasoning, shaped dielectric rods with appropriate excitation mode are designed and placed on the aperture of conventional rectangular and conical horn antennas. The simulation results show that using a shaped dielectric rod inside the horn antenna leads to a decrease in phase-centre variations versus frequency without disturbing the radiation pattern and reflection coefficient. To investigate the performance, a conical corrugated horn antenna loaded by a conical tapered dielectric rod is used as a feed of the transmitarray antenna. Using a shaped dielectric rod fabricated by 3D printing technology, the PC variations of the proposed horn decrease from 1.06 λ to 0.08 λ over the X-band (λ at 8 GHz). The measurement of the fabricated transmitarray antenna shows an improvement of maximum aperture efficiency from 55% to 64.7% at 10 GHz. The aperture efficiency bandwidth above 50% level is also increased from 1 to 2.2 GHz.

Experimental Realization of Silicon Micromachined Terahertz Diplexer-Antenna Module for Heterodyne Receiver

A novel integrated silicon micromachined diplexer-antenna module for compact terahertz (THz) heterodyne receiver is proposed. The module is composed of a radio frequency (RF) antenna, a local oscillator (LO) antenna, and a waveguide diplexer which are realized by using the silicon micromachining technology and stacking nine equal-thickness layers. The corrugated conical horn antenna and quasi-diagonal horn antenna are applied as the RF- and LO-antenna, respectively. The diplexer is composed of two third-order waveguide bandpass filters and an H-plane T-junction, providing the isolated RF and LO channels. An experimental study is carried out in the 340 GHz band, demonstrating its application potential in THz heterodyne receiver element and array.

A Design of an Equalized Gaussian Beam Antenna Applied in A Coal Mine Environment

The environment of confined spaces such as tunnels and coal mines is complex and changeable. When the wireless signal propagates in it, it will be affected by the reflection and diffraction of the shaft wall, which puts forward higher requirements for the radiation beam of the coal mine antenna. In this paper, the corrugated horn antenna model is selected to design a coal mine antenna whose radiation pattern is almost equal to the Gaussian beam. Starting from the expression of Gaussian beam, combined with the radiation field formula of the horn antenna, the effects of slot depth, slot spacing, slot width and horn opening angle on the radiation beam are analyzed. The axial slot corrugated conical horn antenna designed in this paper has a gain greater than 13dBi in the frequency band, the side lobe level is less than -25dB, and the VSWR is less than 1.25 in the designed full frequency band. By comparing the pattern of the horn antenna and the pattern of the Gaussian beam, the results show that the axially grooved corrugated conical horn designed in this paper basically coincides with the Gaussian beam under ideal conditions, and the E and H planes are the Gaussian with a -10dB taper angle of 35°. The beams are basically the same. The equalized Gaussian beam antenna designed in this paper has important guiding significance for the antenna design in coal mine detection and exploration.

Size reduction of a conical horn antenna loaded by multi‐layer metamaterial lens

In this paper, a conical horn antenna in the presence of a metamaterial lens in the X-band is introduced and fabricated. The annular metamaterial lens is located at the aperture of a shortened horn antenna, whose length is half the length of the corresponding optimum horn. The phase velocity in the metamaterial lens is more than the phase velocity along the axis of the antenna for the same propagation distance, so the phase distribution at the aperture of the antenna is uniform and the gain of the shortened horn antenna increases. Metamaterial cells are designed in the form of a printed circuit board that have easy to build and suitable cost. The design process is based on how the waves incident on the proposed metamaterial cell, and finally, by using the particle swarm optimisation (PSO) algorithm proper radiation characteristics in the desired frequency range can be achieved. The radiation characteristics of an antenna with a metamaterial lens are similar to that of an antenna with optimum length in the desired frequency band. The difference is that the weight and volume of these antennas are reduced, so they have better performance in satellite and radar systems.

Designing Cassegrain antenna with axially corrugated horn feed and investigating the effects of the feed antenna gain on optimum dimensions and specifications of the Cassegrain antenna

In this paper, geometric dimensions of Cassegrain antenna are designed in the case of the use of axially corrugated conical horn antenna as the feed antenna. The main issue in the design of the Cassegrain antenna is to calculate the dimensions of the feed antenna and the subreflector antenna so that the amount of aperture obstruction can be minimised and the radiation efficiency is increased. After presenting the design method, an illustrative design example is mentioned. Also the effects of selecting different gain values for the feed antenna, on the dimensions and characteristics of the structure is studied.

3D Printed Linearly Polarized X-Band Conical Horn Antenna and Lens

A low-cost method to 3D print and metalize circular waveguide components is demonstrated using polylactic acid (PLA) and aluminum adhesive backed tape. A gradient index (GRIN) lens, an externally metalized thin-walled conical horn, and a WR90 rectangular to linearly polarized circular waveguide transition are simulated, fabricated, and measured. The horn and lens were both monolithic prints that were externally metallized to simplify the metallization process. Both the horn and lens have a measured operational bandwidth of 8.2 GHz to 12.4 GHz with an input reflection less than -15 dB and peak gain of 18.7 dBi at mid-band. The walls of the thin-wall horn are printed at a thickness such that the dielectric layer does not impact the performance of the horn while being robust enough to support external metallization. The lensed horn functioned as the support for the aluminum foil while also improving the radiation pattern by improving the E SLL by up to 15 dB compared to the thin-walled horn antenna.

An Optimal 18 m Shaped Offset Gregorian Reflector for the ngVLA Radio Telescope

This article describes the design of the 18 m shaped offset Gregorian reflector system for the Next Generation Very Large Array (ngVLA) radio interferometer and the associated 1.66:1 axially corrugated conical horn antennas. A parametric sweep determined feed horns with the goal of pattern symmetry and low spillover efficiency. Given these feeds, a mapping function for the shaped offset Gregorian reflector system was then determined, by a full-factorial design, to achieve maximum receiving sensitivity with secondary parameters such as plate scale, scan loss, sidelobe, and cross-polarization at acceptable levels. A subreflector extension is included in a feed-down tipping configuration with improved performance over the feed-up case. The resultant optics and feeds achieve very symmetrical patterns with an aperture efficiency of around 95%, a plate scale of 15 arcsec/mm, and first and second sidelobe levels of −18 and −24 dB, respectively. The receiving sensitivity at 30 GHz is 8.7 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /K and it increases to above 12 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /K at 12.3 GHz and reduces to 1.5 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /K at 116 GHz (ignoring the efficiency loss due to nonideal reflector surfaces). These sensitivities are close to the theoretical optimum.

High-Resolution Technique for Near-Field Power Density Measurement Accounting for Antenna/Body Coupling at Millimeter Waves

This letter introduces a technique for the power density (PD) pattern measurement in the near field taking into account the antenna/body coupling at millimeter waves (mmW). The proposed method employs a specifically designed structure reproducing the reflection coefficient from human skin. This structure is optimized to convert the absorbed PD into an infrared (IR) pattern, remotely recorded using a high-resolution IR camera for reconstruction of the PD distribution. As a validation example, numerical and experimental distributions are presented for a four-element patch antenna array and a conical horn antenna at 60 GHz. A very good agreement is demonstrated between simulations and measurements (correlation > 98%). The results suggest a strong potential of this technique for fast remote high-resolution PD measurements applied to characterization of wireless devices in vicinity of the human body.