Single Horn Research Articles

Antenna-waveguide devices with a single horn for satellite communication antenna systems

A technical and recommendations for their use in the development and practical implementation of devices as part of antenna-waveguide paths with a single horn are presented to increase efficiency in monitoring MPA satellite communication systems. The practical implementation of multi-band AVP for MPA is shown. Technical solutions for the construction of multi-band AVP for MPA satellite communication systems and remote sensing complexes, which differ from the known ones by the possibility of expanding the functionality of the AVT. Implementation of the monopulse auto-tracking mode using the H21 mode in dual-band auto-tracking machines using signals of specified polarizations in the required frequency ranges. When receiving signals of orthogonal linear and circular polarizations, the number of combined ranges increases to four.

The BINGO Project

Context. The Baryon Acoustic Oscillations (BAO) from Integrated Neutral Gas Observations (BINGO) radio telescope will use the neutral hydrogen emission line to map the Universe in the redshift range 0.127 ≤ z ≤ 0.449, with the main goal of probing BAO. In addition, the instrument’s optical design and hardware configuration support the search for fast radio bursts (FRBs). Aims. In this work, we propose the use of a BINGO Interferometry System (BIS) including new auxiliary, smaller radio telescopes (hereafter outriggers). The interferometric approach makes it possible to pinpoint the FRB sources in the sky. We present the results of several BIS configurations combining BINGO horns with and without mirrors (4 m, 5 m, and 6 m) and five, seven, nine, or ten for single horns. Methods. We developed a new Python package, the <mono>FRBlip</mono>, which generates mock catalogs of synthetic FRB and computes, based on a telescope model, the observed signal-to-noise ratio, which we use to numerically compute the detection rates of the telescopes and how many interferometry pairs of telescopes (baselines) can observe an FRB. The FRBs observed by more than one baseline are the ones whose location can be determined. We thus evaluated the performance of BIS regarding FRB localization. Results. We found that BIS would be able to localize 23 FRBs yearly with single horn outriggers in the best configuration (using ten outriggers of 6-m mirrors), with redshift z ≤ 0.96. The full localization capability depends on the number and type of the outriggers. Wider beams are best for pinpointing FRB sources because potential candidates will be observed by more baselines, while narrow beams search deep in redshift. Conclusions. The BIS can be a powerful extension of the BINGO telescope, dedicated to observe hundreds of FRBs during Phase 1. Many of FRBs will be well localized with a single horn and a 6-m dish as outriggers.

RadarSense: Accurate Recognition of Mid-air Hand Gestures with Radar Sensing and Few Training Examples

Microwave radars bring many benefits to mid-air gesture sensing due to their large field of view and independence from environmental conditions, such as ambient light and occlusion. However, radar signals are highly dimensional and usually require complex deep learning approaches. To understand this landscape, we report results from a systematic literature review of ( N =118) scientific papers on radar sensing, unveiling a large variety of radar technology of different operating frequencies and bandwidths and antenna configurations but also various gesture recognition techniques. Although highly accurate, these techniques require a large amount of training data that depend on the type of radar. Therefore, the training results cannot be easily transferred to other radars. To address this aspect, we introduce a new gesture recognition pipeline that implements advanced full-wave electromagnetic modeling and inversion to retrieve physical characteristics of gestures that are radar independent, i.e., independent of the source, antennas, and radar-hand interactions. Inversion of radar signals further reduces the size of the dataset by several orders of magnitude, while preserving the essential information. This approach is compatible with conventional gesture recognizers, such as those based on template matching, which only need a few training examples to deliver high recognition accuracy rates. To evaluate our gesture recognition pipeline, we conducted user-dependent and user-independent evaluations on a dataset of 16 gesture types collected with the Walabot, a low-cost off-the-shelf array radar. We contrast these results with those obtained for the same gesture types collected with an ultra-wideband radar made of a vector network analyzer with a single horn antenna and with a computer vision sensor, respectively. Based on our findings, we suggest some design implications to support future development in radar-based gesture recognition.

Revisiting the South African Unicorn: Rock Art, Natural History and Colonial Misunderstandings of Indigenous Realities

European ideas about unicorns spread across the world in the colonial era. In South Africa, hunts for that creature, and indigenous rock paintings of it, were commonplace. The aim was proof from ‘terra incognita’, often with the possibility of claiming a reward. There has, however, been little consideration of the independent, local creature onto which the unicorn was transposed. During cross-cultural engagements, foreign beliefs in the mythical unicorn and a desire for evidence of its natural history intermixed to an extraordinary degree with local beliefs in a one-horned animal. For over two centuries, colonists and researchers alike failed to realize that the local creature, by chance, resembled the European unicorn. A new synthesis of southern African ethnography, history and the writings of early travellers, missionaries and colonial politicians provides unambiguous evidence that one-horned creatures obtained in local beliefs before the arrival of colonists. Moreover, it shows that these creatures are depicted in South African rock art, and that they are a manifestation of San (Bushman) rain-animals. By ignoring relevant beliefs and images, previous scholars have failed to acknowledge that the South African unicorn was, apart from its four legs and single horn, a creature wholly different from the European one.

Design of an E-sectoral horn based on PRGW technology for 5G applications

AbstractE-plane sectoral horn antenna based on printed ridge gap waveguide (PRGW) technology is designed for 5G applications. It is implemented on the top plate of the PRGW structure to avoid the losses and dispersion associated with conventional feeding mechanisms. The quasi-transverse electromagneticPRGW-based antenna is excited through a planar microstrip transition. First, the single horn antenna element is introduced with the microstrip feeding section. It shows an impedance bandwidth of fractional bandwidth 26% from 45.7 to 55.4 GHz with the realized gain of 12.7 dBi and radiation efficiency of 90%. In order to maximize the realized gain, a four-element linear horn array is introduced. The same impedance bandwidth is maintained with the array having a gain of 18.6 dBi from 45.7 to 55.4 GHz. The overall antenna array performance in the entire operating frequency range is stable with a radiation efficiency around 85%. Three matching sections are implemented to achieve better impedance matching. One is used to match the horn with the feeding aperture via the PRGW line. Another section is designed to match microstrip transition with PRGW ridge. Finally, two-stage quarter wavelength transformers are required to match the power divider with the array feeding network. A prototype of single-element horn antenna was fabricated to verify the concept of the design. Simulated and measured results show that the proposed antenna can operate in the frequency band of 45–55 GHz with good agreement of radiation performance. Moreover, the proposed designs are implemented and simulated using two microwave simulation tools (CST and HFSS) to verify the radiation performance, which exhibits good agreement. The design of an E-sectoral horn antenna and its array with high gain based on PRGW is demonstrated for the first time which is considered a novel issue. It can be integrated with other passive and active elements in communication systems. Thus, it can be a valuable component in 5G communication due to its high gain, compact size and ultra-wide band.

I'm a Unicorn by Helen Yoon

Reviewed by: I'm a Unicorn by Helen Yoon Kate Quealy-Gainer, Editor Yoon, Helen I'm a Unicorn; written and illus. by Helen Yoon. Candlewick, 2022 [32p] Trade ed. ISBN 9781536219760 $17.99 E-book ed. ISBN 9781536229202 $17.99 Reviewed from digital galleys R* 3-6 yrs With a gleeful, matter-of-fact smile, our one-horned protagonist—clearly a calf with a single horn—informs us that they are a unicorn. They meet the main criteria, obviously, but the little one's confidence takes a hit when doing some research. Unicorns apparently poop rainbows, which, despite the variety of veggies and fruits the calf partakes in, is a feat they can't quite yet manage; unicorns' manes "flow like silk," while the puny tuft upon the calf's head decidedly does not; and unicorns' tears turn into lollipops, while those of our now despairing narrator remain stubbornly colorless. When the calf encounters real unicorns, the ashamed wannabe apologizes for claiming their magnificence, only to be reassured by the unicorns that a one-horned calf does, indeed, fit the requirements. The blasé confidence of the horned horses is especially amusing in contrast to the narrator's increasingly frantic self-doubt, and their "all are welcome" message is delivered with a dry, no-nonsense tone that implicitly points to the silliness of some labels. Yoon's art is simple but effective, with the wide-eyed calf and their heavily tabbed research book set against clean white backgrounds, and when the unicorns finally make their appearance, they bring a riot of color and glitter. Pair this with Young's A Unicorn Named Sparkle or Hale's Itty-Bitty Kitty-Corn (BCCB 3/21) as a reminder that you don't need sparkles to be fabulous (though rainbow poop does help). Copyright © 2022 The Board of Trustees of the University of Illinois

Metasurface Near-Field Measurements with Incident Field Reconstruction Using a Single Horn Antenna

Metasurfaces (MSs) are the 2-D equivalent of metaterials, the latter being a class of artificial engineered materials exhibiting peculiar electromagnetic properties [1], [2]. Generally constructed as arrays of deeply sub-wavelength resonant particles on a substrate, the geometry of the particles can be carefully designed to produce transformations of incident waves, including control of phase, amplitude, polarization, and direction of propagation. Recently, a major research direction has been the “intelligent” Metasurface (MS), where the wave transformation can be electrically controlled, which could be a viable means of achieving, in 5G and future wireless communications, the goal of manipulating and optimizing the propagation environment [3] or to even create sophisticated illusions and holograms on the fly [4]. Other topics that have recently been studied are surfaces with time-varying properties [5] and surfaces composed of particles with multipolar moments [6].

Surgical correction of feline uterine prolapse

AbstractA female domestic shorthair cat of unknown age, weighing 2.9 kg, was presented with a single horn of the uterus protruding through the vulva. The cat had a history of recent parturition, delivering four kittens, and was mildly dehydrated and generally stable. The exposed uterine tissue was congested and oedematous, with areas of devitalization and necrosis. Manual reduction of the prolapsed uterus was unsuccessful because of severe oedema. The protruding uterus was amputated, and a midline laparotomy was performed for staged ovariohysterectomy. Postoperatively, the cat appeared healthy with no vulval discharge and no recurrence of clinical signs. This case report demonstrates the different methods involved in the correction of a uterine prolapse.

Enhancing microwave breast cancer hyperthermia therapy efficiency utilizing fat grafting with horn antenna

A breast cancer hyperthermia system has been developed for the targeted of increasing hyperthermia therapy efficiency after lumpectomy surgery with the assistance of fat grafting technique. Enhancing the efficiency of hyperthermia treatment will decrease the required radiation doses after surgery. A fat grafting technique is applied around the tumor region that is located into glandular tissue for the purpose of enhancing wave penetration through glandular tissue. The proposed hyperthermia system employs a single horn antenna operating at 2.45 GHz. Here, a modified hyperthermia system was tested on a hemisphere phantom of two different densities with various tumor sizes at depth 2.8 cm from skin layer. Transmission and reflection coefficients of applied electromagnetic waves at the air-phantom interface were calculated analytically. Based on these computations, an external dielectric matched layer was added on the skin layer of breast to decrease reflection that would occur at the skin layer because of the difference in permittivity values. The experiments were conducted on a 3-D phantom that has the realistic dielectric properties using the available laboratory capability. Measured and simulated results confirmed the system ability to increase the diseased region temperature using fat grafting technique with a dielectric matched layer without increasing the system input power.

Design and simulation of the new ultrasonic atomizer using silicon-based with one step resonator

The design and simulation of a new generation Fourier amplifier were investigated in this study. The design and characterization of 500 kHz micro fabricated silicon-based ultrasonic atomization is presented for the concept of uniform and fine droplets. Ultrasonic atomizer nozzle is composed of a silicon-based resonator consisting of the Fourier-Horn., drive section and one step part. The atomization of liquid droplets is verified by using the direct modeling CAD software Space Claim and to construct a single and three Fourier-Horn Amplifier model. At the same time, the multi-section geometric model is completed by the array geometry function of the CAE numerical software COMSOL and the physical characteristics of the Fourier amplifier designed by the finite element analysis module. The simulation study states that the onset amplitude of single Horn ultrasonic atomizer produces to 6.8 μm droplets with a designated frequency of 492 kHz. The types and basic principles of mechanical amplifiers (Horn) and the reason for choosing and the designing of required Fourier amplifiers are explained. The simulation data fit well with experimental data. Micro-droplets are steady and uniformly formed after the liquid feeding rate is optimized. This newly designed ultrasonic atomizer facilitates the development of capillary surface-wave resonance at a designated frequency and easy to form atomization of a liquid drop.There are many uses for uniform and fine droplets, for example, it can be used as a precursor for making micro-sized drops, and can be used as a coating to form extremely fine surfaces; it can increase the surface of droplets, increase evaporation speed and even fuel rate; can be suspended Drugs enter the lungs directly and are absorbed into the blood, treatment of inner ear diseases, nose diseases, and even eye cares can use this single Horn atomizer with a tube.

The ACDC horn: A 5-valve single B-flat horn with E-flat alto and F slides

The ascending/descending (or ACDC) horn is a single horn with ascending high E-flat and descending F valves. Its design is simple and composed of a standard 3-valve single B-flat horn fitted with these additional E-flat alto and F valves. This horn can be set to A stopping functionality by pressing simultaneously on both these valves. This latter incidental discovery allows us to propose the first 5-valve single horn which admits a complete range of tonalities, including stopped harmonics, without the need of any additional slide or clutch valve, and with fingerings similar to the standard F/B-flat double horn. With this model, we think the single horn becomes now a serious alternative to the standard double horn.

Mie resonator method for reliable permittivity measurement of loss-less ceramics in microwave frequency at high temperature

This paper describes a new approach, based on the Mie theory, to measure the dielectric properties of lossless materials at temperatures greater than 1500 °C. For the reliable operation of microwave transmitting materials in harsh environments, it is crucial to correctly characterize the permittivity under various temperature conditions. Heating and measurement systems using a propane torch and a single horn antenna were designed to estimate such dielectric properties. The reflection spectrum of Al2O3 ceramics at room temperature was determined using the Mie theory to derive the permittivity and validate the approach. High-temperature dielectric constants are derived from simulated values, which are reliable and have only a slight slope as a function of temperature. These results indicate that the permittivity measurement technique can provide powerful information for the optimal design and accurate evaluation of the dielectric properties of various lossless materials at high temperatures.

Investigation of the characteristics of low-cost and lightweight horn array antennas with novel monolithic waveguide feeding networks

3D printed X-Ku band single horn antenna and 2 × 1 and 2 × 2 pyramidal horn array antennas with novel lightweight and monolithic waveguide feeding networks (WFNs) are proposed at 10–15 GHz for satellite communications and radar systems to increase the gain. Proposed novel fabrication method consists of two main steps that are to make the skeleton of horn array antenna from acrylonitrile butadiene styrene (ABS) thermoplastic via 3D printer and to perform copper plating over all surface of antenna by using the electroless plating and electroplating processes. The WFN structures with 3λ element spacing designed and realized by using WR75 waveguide T-junction, E-type bend, and UDR 120 flange. Qualitative agreement between measurement and simulation via CST Microwave Studio is obtained with max 1 dB due to high precision and surface roughness. The gains of array antennas are increased by about 1.5 dB and 3 dB, respectively compared to the single antenna. VSWRs of array antennas are 0.3 dB and 0.6 dB, respectively higher than the single one. In the study, proposed 3D printed components not only with 90% lighter weight than, but also with 80% cheaper than commercial products, and horn arrays with -40 dB cross-polarization values.

Development of Low Density, Heat Resistant and Broadband Microwave Absorbing Materials (MAMs) for Stealth Applications

The development of low density and broadband microwave absorbers are the need of the hour to cater for the needs of all military platforms for stealth technology. The low density and broadband properties can be inculcated in microwave absorbers using dielectric lossy materials (e.g. carbon fibres, carbon nanotubes, carbon black, fullerene, graphite, graphene and silicon carbide fibre). Therefore, we designed low density and heat resistant microwave absorbing materials (MAMs) using a novel approach of ceramic fibre board manufacturing technology. The microwave absorbing composites were prepared with varying percentage of milled carbon fibres, discontinuous aluminosilicate fibres and silicone resin as the matrix. The physico-mechanical properties of microwave absorbing composites were determined. Reflection loss of microwave absorbing composites was measured in the frequency range 2–18 GHz by unique single horn interferometry technique. The electromagnetic properties were measured in X-band using free space measurement system. Based on these properties the effect of thickness on the microwave absorbing properties in X-band was simulated The effect of weight % variation of milled carbon fibres on the microwave absorbing properties of composites have been studied in the frequency range 2–18 GHz.

Directionality and gain of small acoustic velocity horns.

Acoustic Velocity Horns (AVHs) are acoustically small funnels open to incident acoustic waves from mouth and throat (for single horns) or both mouths for double horns. Unlike traditional pressure horns terminated at the throat, AVHs yield appreciable amplification of the particle velocity across a wide frequency range starting from extremely low infrasound frequencies. Such horns can be utilized to enhance the performance of conventional vector and acoustic intensity sensors. The present paper includes derivation of directional properties and gains for acoustic velocity as well as pressure for horns of various configurations: single and symmetrical double-horns, and symmetrical horns with inserts of various profiles. The study reveals that the conical double-horns provide the highest velocity gain as compared to horns with an exponential profile or with inserts. The maximum gain cannot exceed a horn's mouth-to-throat radii ratio. In addition to the velocity gain, AVHs offer dipole directionality for the particle velocity and omnidirectional response with no gain for acoustic pressure. These findings were experimentally validated using a water-submerged conical double-horn.

Frequency‐selective surface‐based chipless passive RFID sensor for detecting damage location

Various types of wireless sensor systems are used for structural health monitoring. Especially, chipless wireless sensors are useful in harsh environmental conditions of high temperature and toxic chemicals. This paper reports a chipless passive structural health monitoring sensor made with frequency-selective surface (FSS) array for detecting damage location. FSS is a kind of microwave meta-material antenna that is selective by its electromagnetic characteristics associated with geometrical shape and electrical impedance. An FSS-array-based wireless sensor was made on a flexible substrate that can be easily attached to arbitrary structures. When microwaves are applied to the FSS via a single horn antenna, the sensor senses its reflection changes, and by scanning the horn antenna, the location of damage is detected. Design, fabrication, and characterization of cross-type FSS array are carried out, and a computer simulation is performed for comparison.

Study and characterization of E.M. absorbing properties of EPDM ferrite composite containing manganese zinc ferrite

EPDM rubber has been used as matrix and manganese–zinc ferrite as magnetic filler. EPDM ferrite composites were prepared with varying loading in different compositions of Mn–Zn ferrite (RFC-1, 2, 3 and 4) and moulded in the test samples of different thicknesses i.e. 1.5 mm, 2.5 mm and 5 mm. Physico-mechanical properties of EPDM ferrite composites were determined. Complex permeability and permittivity parameters of rubber ferrite composites were measured using rectangular waveguide in the frequency range of 3.95–5.85 GHz. The variation of reflection loss (RL) of single layer rubber-ferrite composites has been investigated as a function of frequency, ferrite content and thickness of composites by unique single horn interferometry technique in the frequency range of 2–18 GHz. It is observed that microwave absorption of rubber–ferrite composites has increased with increase of ferrite content as well as thickness in the frequency range of 2–18 GHz.

Successful outcome of multifetal pregnancy in a single horn of a bicornuate uterus: a case report

Successful outcome of multifetal pregnancy in a single horn of a bicornuate uterus: a case report

Management of Hematometra in Single Horn of Didelphic Uterus with Obstructed Hemivagina and Ipsilateral Renal Agenesis Syndrome: A Case Report with Brief Review of Literature

ABSTRACT The triad of uterus didelphys with obstructed hemivagina and ipsilateral renal agenesis (OHVIRA) syndrome is a rare entity. These cases are difficult to diagnose due to heterogeneous presentation and rarity of the condition. Ultrasonography and magnetic resonance imaging are important for initial diagnosis; however, laparoscopy is required for the confirmation of the diagnosis. Early and accurate diagnosis of this condition followed by prompt surgical therapy is essential to prevent complications and to preserve future fertility. Here we report a case of uterus didelphys with hemivagina and ipsilateral renal agenesis with hematometra and hematosalpinx in a young girl. How to cite this article Mishra VV, Agarwal R, Bandwal P, Choudhary S, Gandhi K. Management of Hematometra in Single Horn of Didelphic Uterus with Obstructed Hemivagina and Ipsilateral Renal Agenesis Syndrome: A Case Report with Brief Review of Literature. J South Asian Feder Obst Gynae 2016;8(3):231-235.

Bone Marrow-Derived Stem Cell (BMDSC) transplantation improves fertility in a murine model of Asherman's syndrome.

Asherman's Syndrome is characterized by intrauterine adhesions or fibrosis resulting as a consequence of damage to the basal layer of endometrium and is associated with infertility due to loss of normal endometrium. We have previously shown that bone marrow derived stem cells (BMDSCs) engraft the endometrium in mice and humans and Ischemia/reperfusion injury of uterus promoted BMDSCs migration to the endometrium; however, the role of BMDSCs in Asherman's syndrome has not been characterized. Here a murine model of Asherman's syndrome was created by traumatizing the uterus. We evaluate stem cell recruitment and pregnancy after BMDSCs transplantation in a model of Asherman's syndrome. In the Asheman's syndrome model, after BMDSC transplant, the Y chromosome bearing CD45-cells represented less than 0.1% of total endometrial cells. Twice the number of Y+CD45- cells was identified in the damaged uterus compared to the uninjured controls. There was no significant difference between the damaged and undamaged uterine horns in mice that received injury to a single horn. In the BMDSC transplant group, 9 of the 10 mice conceived, while only 3 of 10 in the non-transplanted group conceived (Chi-Square p = 0.0225); all mice in an uninjured control group conceived. The time to conception and mean litter size were not different between groups. Taken together, BMDSCs are recruited to endometrium in response to injury. Fertility improves after BMDSC transplant in Asherman's Syndrome mice, demonstrating a functional role for these cells in uterine repair. BMDSC transplantation is a potential novel treatment for Asherman's Syndrome and may also be useful to prevent Asherman's syndrome after uterine injury.