Showing papers on "Feed horn published in 2020"

Wideband Transmit Arrays Based on Anisotropic Impedance Surfaces for Circularly Polarized Single-Feed Multibeam Generation in the Q-Band

Abstract: In this article, a class of wideband transmit arrays (TAs), composed of cascaded anisotropic impedance surfaces (AISs), for circularly polarized (CP) multibeam generation from a single feed horn are reported. The dispersionless phase compensation is achieved by the Berry phase (BP) via imposing a spatially dependent rotation angle on the TA unit cells. A homogenized model for the BPTA unit cell is proposed and utilized for obtaining a wideband response by tailoring the dispersive properties of the AIS layers. Two modeling methods, an analytical vectorial field analysis and a full-wave strategy incorporating the homogenized model, were employed to efficiently evaluate the performance of the BPTAs. In order to validate the proposed unit cell and the modeling methodologies, a Q-band single-beam BPTA is demonstrated, which achieves a peak gain of 30.2 dBi and a 1 dB bandwidth of 11.1% within which the axial ratio is smaller than 2 dB. Furthermore, by employing the intersection approach for pattern synthesis, several Q-band BPTAs supporting multiple concurrent symmetric/asymmetric CP pencil beams and circular-shaped flat-top beams are designed. A BPTA prototype for producing quad CP pencil beams with unequal gain values was fabricated and characterized, yielding good performance with an overall operational bandwidth of about 11%. The proposed BPTAs are promising candidates for point-to-multipoint communication and point-to-multiregional coverage in wideband millimeter-wave communications for wireless and satellite applications.

A 2-D Beam-Scanning Bessel Launcher for Terahertz Applications

Abstract: This article proposes a novel nondiffractive Bessel beam launcher based on discrete dielectric lens (DDL) antenna with 2-D beam-scanning capability operating at 300 GHz. The terahertz (THz) Bessel beam launcher consists of two identical in-plane rotatable DDLs fed by a commercially available pyramid horn. First, the two thin and lightweight DDLs can transform the quasi-Gaussian beam with spherical phase front from the feed horn into a well-collimated and confined pseudo-Bessel beam. Second, we demonstrate that simultaneous in-plane rotation of the two DLLs in the same and opposite directions can steer the generated Bessel beam in the azimuth and elevation, respectively. Hexagonal dielectric post is employed as the element of the DDL, whose height is tuned from pixel to pixel to realize the required aperture phase distribution. 3-D printing technology was utilized to fabricate the two DDLs aiming at simplifying the manufacturing process and reducing the cost. The theoretically calculated, simulated, and measured results reveal that the designed THz DDL can generate 2-D scanning nondiffractive Bessel beam with a large field of view (FoV) of 86.2° and full azimuth coverage. The proposed 2-D scanning THz Bessel beam launcher can find widespread applications in THz fast noncontact detection, tracking, and imaging systems.

Beam scanning antenna based on parabolic phase distribution lenses

Abstract: In this study, the authors present a beam scanning lens antenna for 30 GHz applications, which is composed of a feed horn and a planar lens with parabolic phase distribution. Due to the parabolic phase compensation, the lens antenna can perform the scanning coverage of ±60° with a gain tolerance of 3 dB. The fabricated lens has a size of 10λ0 × λ 0 × 0.2 λ 0 ( λ 0 is wavelength at the centre frequency of 30 GHz) and the focal length of 24 mm. The beam steering mechanism and the phase error of the lens antenna are analysed in detail. The total system has the advantages of wide scan angle, low profile and lightweight, and it can be readily applied to multi-beam or beam-scanning antenna designs.

Design and Analysis of Terahertz Transmitarray Using 1-bit Liquid Crystal Phase Shifter

Abstract: This paper presents a 1-bit terahertz liquid crystal (LC) beam-steering antenna. It consists of a feed horn antenna and a flat rectangular transmitarray with 20×20 LC phase shifter unit cells. The unit cell could achieve phase difference within 180°±20° from 329 to 366.4GHz using double-layer of LC when the permittivity of the LC varies between 2.37 (state 0) and 3.29 (state 1). The full wave simulation results indicate that it can realize beam scanning over ±40° at 340GHz. The gain of the transmitarray is more than 21.4dBi.

Circularly Polarized Axially Corrugated Feed Horn for CubeSat Reflectarray Applications

Abstract: Reflectarray (RA) and transmitarray (TA) antennas that use the element-rotation technique require the radiation from the feeding antenna to be circularly polarized (CP). A CP axially corrugated horn antenna is developed as a feeding element for CubeSat RA and TA antennas. The CP operation is enabled using a septum polarizer. The all-metal geometry is attractive for space applications and allows the horn to be 3D printed in aluminum in a single piece. A prototype of the feed chain was fabricated using the Direct Metal Laser Sintering (DMLS) technique. The results of 3D simulations and VNA/far-field measurements of the feed chain are presented in this paper.

Q-band receiver system design for the Canadian DVA-2 radio telescope

Abstract: A compact front-end system is presented for a dual-linear polarization cryogenic Q-band receiver. This receiver will be used to demonstrate the high frequency performance of the Dish Verification Antenna 2 (DVA-2) composite reflector telescope between 35–50 GHz and is a technology demonstrator with possible application to the National Radio Astronomy Observatory’s Next Generation Very Large Array (ngVLA). A vacuum vessel and a two-stage Gifford-McMahon cryopump system are used for the cryogenic environment. The second stage of the cryostat is cooled to 16 K and includes a small choke ring feed horn, a low-loss noise calibration module (NCM) integrated with orthogonal mode transducer (OMT), and two cryogenically cooled mHEMT MMIC low-noise amplifiers (LNAs). Using a noise diode as the noise source on the 300 K stage inside the cryostat helps to protect the cooled components from signals outside of the cryostat, and also lessen the heat on the second stage since a noise diode normally produce a power dissipation of several hundred mW. The OMT design is an optimized version of the design used in the ALMA Band 1 cartridge with two integrated directional couplers and excellent performance. The cascaded noise analysis of the receiver shows a receiver noise temperature of 19.4 K.

3-D Printed Terahertz Lens for Generation of Non-diffractive Bessel Beam Carrying OAM

Abstract: A novel 3-dimensional (3-D) printed lens for high-order Bessel beam generation operating at 300 GHz is proposed in this paper. The designed terahertz (THz) lens can transform the spherical wave-front from the feed horn into non-diffractive Bessel beam carrying orbital angular momentum (OAM). The lens consists of discrete dielectric posts, whose height can be tuned from pixel to pixel to realize the desired aperture phase distribution. Furthermore, 3-D printed technology is used to fabricate the lens with low cost. Measured results demonstrate that the designed 3-D printed lens can generate THz non-diffractive Bessel vortex beam carrying OAM.

3-D Printed Terahertz Lens with 2-D Near-Field Focus-Scanning Capability

Abstract: A novel near-field focus (NFF) lens antenna with two-dimensional (2-D) focus-scanning capability operating at THz frequencies is proposed in this paper. The NFF antenna consists of a pair of thin and lightweight discrete dielectric lens (DDL), which is placed above a stationary feed horn. The DDL pair is designed to emulate the functionalities of a conventional bulky four-refractive-lens NFF system. To simplify the manufacturing process and reduce the cost, 3-D printing technology is adopted to fabricate the lens antenna with a radius of 7.5 mm operating at 0.3 THz. Experimental results demonstrate that the antenna is capable of realizing 2-D nearfield focus scanning by mechanically in-plane rotation of the two DDL panels.

Design and analysis of three Q-band Feed Horns for Radio astronomy applications

Abstract: Three different feed horn antennas for radio astronomy applications are presented in this paper. Feed structures including Choked ring horn, conical corrugated horn, and exponentially shaped quad-ridged horn are designed and simulated. Circular waveguide with same diameter is used for exciting the dominant TE11 mode in the input of all proposed antennas. The performance of each feed horn regarding the beamwidth, gain, cross polarization and side lobe levels are investigated in Q-band frequency range.

Earth coverage antenna system for Ka-band communication

Abstract: An earth coverage antenna system includes a reflector, a feed horn and a strut. The reflector has a circularly symmetric reflector surface. The feed horn is positioned on the symmetry axis of the reflector and is attached to the strut. The feed horn transmits RF microwave energy toward the reflector surface. The antenna system further includes two cables that prevent side-ways movement of the strut. The antenna system further includes a lens assembly that directs microwave energy away from the central region of the reflector. The antenna system further includes a microwave energy scattering device disposed at the center of the reflector to scatter microwave energy away from the feed horn. The reflector surface is defined by a perturbed parabolic geometrical shape that is swept around the symmetry axis. The reflector reflects most microwave energy towards the earth's horizon, but diverts enough microwave energy towards the regions closer to nadir so as to maintain an isoflux of energy on the earth's surface. The reflector shape is optimized to minimize flux ripples caused by interference of the microwave energy scattered from the microwave energy scattering device.

Wide band log periodic reflector antenna for cellular and Wifi

Abstract: An antenna having a feed horn assembly, a parabolic reflector assembly, and a mounting bracket assembly. The feed horn assembly has a circuit board housing having first and second molded housing halves and a main support arm. The feed horn assembly is adjustable, whereby the main support arm is adjusted from a collapsed configuration to an elongated configuration and vice-versa. The feed horn assembly further has a printed circuit board, a coaxial feed cable, an arm holder, and a coaxial radio frequency connector. The printed circuit board is triangular in shape. The circuit board housing houses the printed circuit board. The main support arm has a plurality of arm adjustment holes and extends from the arm holder to the circuit board housing. From the collapsed configuration to the elongated configuration there are intermediate configurations. The antenna has single polarization.

High-performance dual-polarized antenna feed chain

Abstract: Antenna feed chains and methods are disclosed. An antenna feed chain, include a feed horn having a first cross-polarization performance over a solid angle of interest and a frequency band of interest and a polarizer having a second cross-polarization performance over the solid angle of interest and the frequency band of interest. The polarizer is coupled to the feed horn. The first cross-polarization performance of the feed horn compensates for the second cross-polarization performance of the polarizer over the solid angle of interest and the frequency band of interest.

Antenna Design and Prelaunch Performance of a Low-Cost 118.75 GHz Temperature Sounding CubeSat Radiometer With 3-D-Printed Corrugated Feed and Offset Reflector Optics

Abstract: This article describes the design and prelaunch performance of the antenna subsystem of the low-cost 118.75 GHz temperature sounding radiometer payload used in the PolarCube and GEMS-IOD 3U CubeSat missions. Radiometric sounding measurements used for providing data for weather prediction are strongly affected by the main beam, ohmic, and spillover efficiencies of the optics, as well as by inhomogeneities in the scene and background radiation fields. The interpretation of radiometric data is affected by the accuracy with which these antenna efficiencies can be determined, particularly for radiometers that do not permit full main beam external calibration. To this end, an HE11 mode full wave Fourier–Bessel electromagnetic field analysis was developed for determination of an optimal feed horn and reflector geometry such that the main beam and spillover efficiencies of the system are maximized, and these and the antenna phase center location that maximizes phase efficiency are precisely known. The efficacy of employing a sub-millimeter wave 3-D-printed corrugated conical horn operable between 110 and 127 GHz as the feed for an offset paraboloidal reflector due to its very low cost and rapid manufacturability is also addressed. Horn measurements indicate a reflection coefficient below −15 dB and far-field radiation patterns that compare closely to simulation. Although there is some asymmetry in the horn pattern, the average main beam efficiency is 89% for a main reflector subtending a 16° half-angle. Initial performance obtained from airborne measurements over Antarctica on the NASA DC-8 during Operation IceBridge in Oct–Nov 2016 suggests a well-focused scanning antenna subsystem. After final payload assembly, the antenna’s 3 dB beamwidth extracted from a bridge-scan field experiment was broader by ~ 0.1° compared with the idealized simulated pattern.

Frequency selective surface zoning technique

Abstract: A method for providing frequency selective surface zoning includes selecting a location for positioning a frequency selective surface (FSS) panel along a support arm of a reflector antenna system, and positioning a second feed horn on the support arm on an opposite side of the FSS panel A number of unit cells are used to populate the FSS panel, and metallic patterns are formed on each unit cell Multiple zones are subsequently defined on the surface of the FSS panel Each zone is optimized for a predetermined range of incident angles

Design of Horn Feed with Duplex Function for Parabolic Antennas in Ku-Band VAST Applications

Abstract: A horn feed with duplex function for parabolic antennas is designed in this paper. The proposed feed integrates a horn and an E-plane split waveguide duplexer. The E-plane split waveguide duplexer consists of two Ku-band waveguide filters, which are designed by inserting diaphragms into the rectangular waveguide. In parabolic antenna, the innovation of this paper is that the integration of the duplexer into the feed horn not only plays the role of self-supporting, but also reduces the size of the whole structure. The proposed horn feed provides a good gain of 9.5dBi in the transmitting band and 8.4dBi in the receiving band respectively. This horn feed can be used for Ku-band Very Small Aperture Terminal (VSAT) applications with receiving and transmitting frequencies of 11-11.8GHz and 14.1-15GHz, respectively. The proposed horn feed shows a good isolation of over 45dB in the transmitting channel and over 60dB in the receiving channel.

Marine satellite communication antenna system for high-speed ship

Abstract: The present invention relates to a maritime satellite communication antenna system for a high-speed ship that is capable of performing tracking even in the event of a sharp turn of a high-speed ship. The antenna system includes: an antenna assembly including a main reflector, a feed horn, and a sub-reflector rotated at a high speed by a scan motor; a downstream circuit unit for receiving a satellite signal of a target satellite from the feed horn through low-noise amplification; an upstream circuit unit for transmitting a transmission signal to the target satellite through the feed horn after high-frequency amplification; a plurality of control modems for transmitting a control signal between an antenna deck and an operation room; a pedestal control unit receiving a detection signal input from a scan sensor and causing the antenna assembly to track the target satellite by controlling a yaw motor, a pitch motor, a roll motor, a pole motor, a tilt motor, and the scan motor in accordance with the control signal transmitted through the control modems; and an antenna control unit transmitting a control signal to the pedestal control unit through the control modem so that the target satellite is tracked by means of the satellite signal received through the downstream circuit unit and performing control so that tracking can be continuously performed based on ship and target satellite location signals in the event of a tracking failure. According to the present invention, it is possible to perform tracking even in the event of a sharp turn of a high-speed ship during automatic satellite tracking based on high-speed tilting or eccentric rotation of the sub-reflector.

Satellite antenna lnb fixing apparatus

Abstract: Provided is a satellite antenna LNB fixing apparatus capable of easily coupling an LNB (10) integrated with a feed horn to an antenna without a separate tool, coupling an LNB (10) integrated with various types of feed horns to the antenna using a single or a few fixing apparatuses, and easily changing a polarization angle of the LNB.

Focusing metasurface reflection array antenna and preparation method thereof

Abstract: The invention discloses a focusing metasurface reflective array antenna and a preparation method thereof. The reflective array antenna is composed of a feed horn and 3600 phase shift units, a complexfeed network is not needed, the manufacturing process is simple, the processing cost is low, and the array is a plane and is easy to disassemble and transfer. Each unit patch is composed of a square ring and a concentric square ring, so that the phase shift compensation range is large, and phase shift is not sensitive to machining errors. Meanwhile, a phase shift unit is high in area utilization rate, reflection characteristic is good and loss is low; multi-point focusing is adopted on the axis, so that the antenna maintains high transmission efficiency in a long distance; and finally, the energy transmission efficiency within the range of 10 m reaches 45% or above, and the antenna is suitable for application and popularization in the field of microwave wireless energy transmission.

Front end concept development for a next generation Very Large Array

Abstract: The ngVLA Front End concept has six separate cryogenically-cooled, dual polarization receiver bands, each with an integral feed horn. The upper five bands (2–5) are co-located within a single compact cryostat, while the lowestfrequency band (1) occupies a second cryostat of similar volume and mass. For optimum performance at higher frequencies, waveguide-bandwidth (~1.66:1) receivers are used above 12 GHz, with axially-corrugated feed horns for high aperture efficiency and low spillover. Below 12 GHz, wideband (~3.5:1) receivers and feed horns are used to reduce receiver count, total mass, and cost, with modest trades in sensitivity. Ongoing work includes development of wideband feed horns, windows, low-noise amplifiers (LNAs) and couplers for Bands 1–2, design or procurement of orthomode transducers (OMTs) and LNAs for Bands 3–6, and detailed mechanical design of the conceptual Front End cryostats and receiver/feed/window subassemblies. Accurate simulations of sensitivity (AEFF/TSYS) versus frequency and antenna elevation will be shown, based on modeled or measured component data and the simulated performance of the antenna optics.

Study of Feed Horn Solutions for Irbene RT-32 Radio Telescope

Abstract: Abstract Various feasible solutions of Irbene RT-32 secondary focus feed antennas are designed and compared in the present study. The examined feed antennas include smooth wall and corrugated horns with linear and shaped profiles. Mode matching technique is employed for simulation of scattering parameters and radiation patterns. Genetic algorithm is used for optimisation of horn profile for the best cross-polarization, and aperture efficiency performance. Although the presented horns are valid for any frequency band, different solutions allow choosing the best combination of factors, such as electrical parameters, bandwidth, physical size and complexity of manufacturing.

Antenna for satellite communication capable of receiving multi-band signal

Abstract: Provided is an antenna for satellite communication capable of receiving multi-band signals. The antenna includes: a main reflector; a first feed horn which is provided on the main reflector and receives a signal of a first band; a first reflector which is disposed to be spaced apart from a reflective surface of the main reflector at a predetermined interval and transmits the signal of the first band to the first feed horn; a second feed horn which is provided on the main reflector and receives a signal of a second band; and a second reflector which is disposed to be spaced apart from the reflective surface of the main reflector at a predetermined interval and transmits the signal of the second band to the second feed horn.

Low Profile Multi Band Antenna System

Abstract: A multi band antenna system for transmission and reception of electromagnetic signals in a low-profile dual reflector configuration with position- controlled main-reflector, and fixed sub-reflector and feed horn An added linear slide of the main-reflector with respect to the sub-reflector synchronized with variable tilt angle of the main-reflector for compensation for the varied focal length in the main- reflector to the beam due the varied main-reflector tilt The system achieves a beam elevation of 10⁰ to 100⁰ (full elevation), minimum gain variations over the full elevation travel, swept volume as per ARINC 791 (eg Boeing Radome or Airbus Radome), and can be used to meet wide-Tx/Rx bands requirements