Showing papers on "Feed horn published in 2005"

Dual frequency radio tag for a radio frequency identification system

Abstract: A dual frequency radio tag for a radio frequency identification system is provided that includes an antenna system and a first receiver coupled to the antenna system. The first receiver receives and processes request signals from a first unit type at a first frequency. A second receiver is coupled to the antenna system and receives and processes request signals from a second unit type at a disparate second frequency. A transmitter is coupled to the antenna system and transmits response signals from the radio tag at the second frequency.

A new dual-polarized broadband horn antenna

Abstract: This letter describes a new design of dual-polarized broadband horn antennas. The bandwidth of the designed horn antenna is from 2 to 26.5 GHz. A novel coaxial line to quadruple-ridged waveguide transition is introduced to improve the return loss performance of the horn antenna. Measured results for VSWR, isolation, gain, and radiation pattern of the designed horn antenna are presented.

Collision alerting and avoidance system

Abstract: A collision alerting and avoidance system for use in an aerial vehicle is presented herein. The system comprises a one low profile antenna array disposed on the aerial vehicle. The array includes a plurality of horns; a polar horn, 45-degree horns, and equatorial horns. A transmitter/receiver probe is coupled to each horn. The transmitter/receiver probes are configured to transmit electromagnetic waves and to receive an echo signal reflected from a threat obstacle. A plurality of transmitter/receiver modules are coupled to each of the transmitter/receiver probes. The transmitter/receiver modules are configured to produce electromagnetic waves for transmission and to receive the echo signal. A processor coupled to the plurality of transmitter/receiver modules controls the transmission of electromagnetic waves from the horns and processes the echo signal to provide an output signal containing information regarding the obstacle.

A dual planar reflectarray with synthesized phase and amplitude distribution

Abstract: A quasi-planar reflector arrangement for generating an arbitrary phase and amplitude distribution in the antenna aperture and thus a wide range of far field patterns is presented. A parallel pair of reflectarrays is used. One is implemented as a standard reflectarray using rectangular patches on a microwave substrate with metallized backside. The other reflectarray is provided with a polarizing grid, which acts as a ground plane for one polarization and is transparent for the orthogonal polarization. An offset rectangular feed horn is embedded in the lower reflectarray to illuminate the upper reflector. A design procedure for a linear polarized antenna with a sector beam in the azimuth and a narrow beam width in the elevation is presented and is verified with measurement results.

Design and simulation of a 1 to 14 GHz broadband electromagnetic compatibility DRGH antenna

Abstract: This work presents the design and simulation of a 1-14 GHz double ridged guide horn antenna (DRGH) with coaxial input feed section. This antenna, due to the large frequency bands required by standards, is suitable to be used in electromagnetic compatibility (EMC) testing. The horn-antenna model analyzed dates back to the early 1970s when J. L. Kerr suggested the use of a feed horn launcher whose dimensions where found experimentally. Although this type of horn has become the preferred test antenna of EMC testing for the 1-18 GHz range, which has been widely used for over four decades, no explanation of the effect of the launcher dimensions and the ridges shape into the flared section on the antenna parameters was found in the open literature. To investigate this phenomenon in detail, the entire horn has been modeled, including the coaxial feed using a time domain method. The simulations indicate that deficiencies in the radiation pattern start to appear at frequencies above 6 GHz and it starts to split at frequencies above 12 GHz. In spite those problems, the designed antenna can work well up to 14 GHz.

The designing, manufacturing, and testing of a dual-band feed system for the Parkes radio telescope

Abstract: This paper presents the designing, manufacturing, and testing of a dual-band feed system for the Parkes radio telescope (Australia). The feed system consists of a coaxial horn and associated feed components to operate in the 648-712 MHz and 2.6-3.6 GHz frequency bands. The manufacturing of such a feed system was challenging, and we present the innovative solutions that were devised to fabricate the different parts of the feed system. Preliminary measurements indicate that the overall system, feed and reflector, is working to operational expectations, and valuable scientific results have already been obtained using the simultaneous dual-frequency capability.

Circular polarity elliptical horn antenna

Abstract: A relatively low cost, easy to install and aesthetically pleasing digital video broadcast from satellite (DVBS) elliptical horn antenna designed as part of a reflector antenna system to receive satellite television broadcast signals with circular polarity. This type antenna may be implemented with a single antenna feed horn with multiple feed horns that may be arranged separately or in one or more integral feed horn blocks. The antennas may be designed to achieve acceptable circular polarity performance over broad and multiple frequency bands through the use of oppositely sloped differential phase differential sections.

Parabolic antenna of a level measuring instrument and level measuring instrument with a parabolic antenna

Abstract: This invention concerns a parabolic antenna with a parabolic reflector ( 2 ) having a parabolic reflector rim ( 20 ), a collar ( 9 ), which is positioned on the parabolic reflector ( 2 ), in particular on the parabolic reflector rim ( 20 ) and which has an outside collar rim ( 90 ), and having an exciter and/or a receiver ( 3 ), such that the exciter and/or receiver ( 3 ) are/is located in the axial direction (X) partly within the parabolic reflector rim ( 20 ) and partly outside thereof.

Fluid level detection using RF

Abstract: The present disclosure includes systems and techniques relating to fluid level detection. In general, in some implementations, a fluid level detector includes a radio frequency transmitter, and a plurality of radio frequency detectors arranged to receive radio frequency signals from the radio frequency transmitter when above a fluid level. The radio frequency transmitter and one or more multiple transmitting antennas can be configured to transmit ultra high frequency (UHF) RF signals. The radio frequency detectors can be radio frequency antennas, and the fluid level detector can include circuitry configured to receive signals from the radio frequency antennas. For example, the circuitry can include a decode array (e.g., a two dimensional diode array) coupled with the antennas, and a decoder (e.g., digital logic) coupled with the decode array.

Method and apparatus for mounting a rotating reflector antenna to minimize swept arc

Abstract: An apparatus and method for mounting a rotatable reflector antenna system on an outer surface of an aircraft which minimizes a swept arc of a main reflector. This allows the effective frontal area of the main reflector to be reduced such that a radome with a smaller frontal area can be employed to cover the antenna system. The main reflector is rotated about an azimuth axis which is disposed forward of an axial center (i.e., vertex) of the main reflector. In one embodiment the azimuth axis is located in a plane extending between the outermost lateral edges of the main reflector, which define the aperture of the antenna. In another embodiment the azimuth axis is located forward of the outermost lateral edges of the main reflector. In further embodiments the azimuth axis of rotation is located in between a subreflector and a feed horn of the antenna, or in between the vertex of the main reflector and the subreflector.

Multimode feed horn providing multiphase centres with offset reflector antenna

Abstract: The investigation results of multimode feed horns are presented, which provide multi-phase centre radiation performance with the reflector. These feed horns with reflector assembly are suitable for radar systems, where ground moving target indicator (GMTI) mode implementation is desired. The simulations were carried out using Ansoft Corporation's HFSS v8.5 for feed horn, and Ticra's GRASP v7.0 for the reflector.

A dual-band mobile radio antenna

Abstract: The invention relates to an antenna, in particular a mobile radio antenna for operation in at least two frequency bands, comprising the following features: the antenna is equipped with several dipole transmitters (2; 3), which are located in front of a reflector (1) and transmit in two different frequency bands; the distance between the transmitter structure, the transmitter elements or the upper face (102) of the transmitter elements of at least one dipole transmitter (2) for the higher frequency band and the reflector plane (E) is at least 75 % and a maximum 150 % of the distance between a transmitter structure, a transmitter element or the upper face (103) of a transmitter element of at least one dipole transmitter (3) for the lower frequency band and the reflector plane (E); and/or the distance between the transmitter structure, transmitter elements or the upper face (102) of the transmitter elements of at least one dipole transmitter (2) for the higher frequency band and the reflector plane (E) is greater than 0.4 A and preferably less than 2 A in relation to the mid-frequency of the transmitter for the higher frequency.

Measurements of a 1 to 13 GHz model of a dual polarized low-profile log-periodic feed for US-SKA

Abstract: We present measured results for a dual polarized 1 to 13 GHz laboratory model of a feed for use in reflector antennas. The main goals of the laboratory model were achieved: it provides dual polarization and can provide more than a decade bandwidth. The aperture efficiency in a primary fed reflector system is greater than 56% over the entire band, and the input reflection coefficient of the feed is better than -5.5 dB. The results agree well with computed values.

Millimeter-wave profiled corrugated horns for the quad cosmic background polarization experiment

Abstract: In this paper we report on the design and validation process for the profiled corrugated horn antennas, which feed the bolometer array of a cosmology experiment known as QUaD located at the South Pole. This is a cosmic background radiation polarization project, which demands precise knowledge and control of the optical coupling to the signal in order to map the feeble E- and B-polarization mode structure. The system will operate in two millimeter wavelength bands at 100 and 150 GHz. The imaging horn array collects the incoming signal via on-axis front-end optics and a Cassegrain telescope, with a cold stop in front of the array to terminate side-lobe structure at an edge taper of –20dB. The corrugated horn design process was undertaken using in-house analytical software tools, based on modal scattering, specially developed for millimeter -wave profiled horn antennas. An important part of the instrument development was the validation of the horn design, in particular to verify low edge taper levels and the required well-defined band edges. Suitable feed horn designs were measured and were found to be in excellent agreement with theoretical predictions.

High power dual band high gain antenna system and method of making the same

Abstract: A high power dual band high gain antenna system is provided. The antenna system employs one or more feedhorn clusters to distribute power associated with the transmission of high power signals. A first feedhorn cluster is associated with a first frequency band and a second feedhorn cluster is associated with a second frequency band that operates in frequencies below the first frequency band. The antenna system includes a sub-reflector and a main reflector with a first focal point of the sub-reflector being substantially aligned with a focal point of the main reflector. The first feedhorn cluster and the second feedhorn cluster are arranged on a surface of the main reflector with radiating aperture phase centers substantially aligned with a second focal point of the sub-reflector.

Reflector, an antenna using a reflector and a manufacturing method for a reflector

Abstract: The present invention relates to a reflector (20; 30; 40) for use in an antenna (10; 50). The reflector (20; 30; 40) is arranged to be used as an earth plane of the antenna (10) and the reflector is corrugated to form current pockets. The reflector (20; 30; 40) comprises at least two separate parts (21, 22; 21, 22, 31, 32; 41, 42), and the parts are electrically coupled to each other to commonly form the earth plane of the antenna (10; 50). The invention also relates to an antenna including a reflector, and to a method for manufacturing a reflector.

Dual-band multiple beam antenna system for satellite communications

Abstract: This paper presents a dual-band antenna system that is suitable for satellite communications at K/Ka-band frequencies. It employs a minimum number of reflectors, each being fed with multiple feed horns. It is shown that the MBA performance in terms of coverage gain and co-polar isolation can be significantly improved by using optimal designs for the feed horn and the reflector. The performance results of this MBA are compared with conventional designs and the trade-offs are discussed.

A 31 pixel flared 100-GHz high-gain scalar corrugated nonbonded platelet antenna array

Abstract: A compact 100-GHz corrugated platelet antenna array has been developed based on a corrugated feed design for the background emission anisotropy scanning telescope (BEAST) optics. The antennas in the array result in a gain of 20 dB, and a bandwidth across the full range of W-band 75-110 GHz. The side lobes are down by about -25 dB, a requirement comparable to feed horns used for observation of the cosmic microwave background. The design and fabrication presented in this letter is straightforward and inexpensive. A feature is that because the plates are not permanently bonded, the horn can be disassembled and modified to change its properties such as addition of flare plates or modified rib structures.

Design and performance of sliced-aperture corrugated feed horn antennas

Abstract: We report on the design of corrugated feed horn microwave antennas at 3.3, 5.6, 7.8, and 10.2 GHz for the absolute radiometer for cosmology, astrophysics, and diffuse emission experiment. These horns have low sidelobe symmetrical beams with 12° full width at half power, and three noteworthy features: a 30° slice at the aperture, a profiled rather than a linear taper, and a slowly varying groove depth along the length of the horn. The profiled taper and varying groove depth provided a narrow beam given the existing physical spatial constraints of the instrument in which the horns are used. The 30° slice was necessary for instrumental considerations and has a minimal effect on the symmetry of the beam. The slice reduces the effective aperture radius and overall length to that corresponding to an unsliced horn with an aperture at roughly the middle of the slice and does not introduce any undesirable effects.

Device and method for visualizing radio wave generation source

Abstract: PROBLEM TO BE SOLVED: To provide a device and a method for visualizing a radio wave generation source that can search for a signal in a frequency range of a broad-band, in a short time, for specifying a radio wave generation source effectively and then can visualize the source. SOLUTION: The device includes an A/D converter that obtains digital data, corresponding to signals received by a reference antenna and a plurality of other antennas, after receiving radio waves inputted to the reference antenna and a plurality of the antennas to frequency-convert the waves, and an arithmetic processor that is operable in two modes, which has one of the modes frequency-analyzes the received signals, based on the digital data of a signal received by at least one of antennas and another mode that receive signals in a specified frequency band for estimating the arrival direction of the radio waves to output two-dimensional images, using the correlation values of digital data of the signals received by the reference antenna and a plurality of the antennas. Then, the mode is selected and controlled, in response to the operation of the operator. COPYRIGHT: (C)2007,JPO&INPIT

Ka-band dual circularly polarized feed horn polarizer for reflector antennas for satellite communications

Abstract: The performance of a Ka-band (20/30 GHz) dual circularly polarized feed polarizer designed for reflector antennas for satellite transmit & receive communications is presented. The arrays of pins have been used as a delay structure to achieve the desired phase shift in both bands.

Analysis and design on aperture antenna systems with large electrical size using multilevel fast multipole method

Abstract: A full-wave procedure for designing electrically large optimized classical- aperture antenna systems is analyzed using the multilevel fast mulitpole method (MLFMA). The useful design equations for optimized offset dual reflector antennas with circular apertures are also presented to allow the size and spacing of the main and subreflectors of the antenna system, along with the feed horn subintended angle, to be used as input variables of the design procedure. The radiation of feed horn is first analyzed and compared with theoretical and available measurement results. The conventional reflector antennas are simulated and analyzed for aperture blockage of the feed. Finally, the offset dual reflector antennas with circular aperture are designed and validated numerically by showing that low cross polarization and spillover losses obtained. All the simulations are made by using the MLFMA which is implemented based on the method of moments (MoM) with RWG triangular patch basis function to model any shape of reflector surfaces.

A low power radio device with reduced interference

Abstract: A low power radio device, operable in a first radio system, comprising: a detector for detecting the polarization of an antenna of a further radio device, operating in a further radio system, different to the first radio system; and a transmitter for controlling the polarization of a transmitted radio signal in dependence on the detected polarization. The polarization of the transmitted signal may be controlled to be substantially orthogonal to the polarization of the antenna of the further radio device.

3D Optical microstructure fabrication and its bonding to micro IR detector using elastomeric polymer

Abstract: This paper describes polidimethylsiloxane(PDMS) based bonding for assembly of microstructure device, an UV lithography applications for fabricating a 3-dimensional (3D) feed-horn-shaped structure mold array, and obtaining parallel light by using a mirror-reflected parallel-beam illuminator (MRPBI) system. A 3D feed-horn-shaped micro-electro-mechanical systems (MEMS) antenna has some attractive features for array applications, which can be used to improve microbolometer performance and to enhance the optical efficiency for thin film transistor-liquid crystal display (TFT-LCD) and other display devices but currently, MEMS technology has faced many difficulties in the fabrication of a 3D feed-horn-shaped MEMS antenna array itself. The purpose of this paper is to propose a new fabrication method to realize a 3D feed-horn-shaped MEMS antenna array by using a mirror-reflected parallel-beam illuminator (MRPBI) System with a very slowly rotated, inclined x-y-z stage. With a conventional UV lithography apparatus, it is very difficult to fabricate high-aspect-ratio structures (HARS) because a typical UV lithography apparatus cannot produce perfectly parallel light. From a theoretical analysis, a columnar illuminator over 6 m in height is required to achieve parallel light, but generally a laboratory height is not 6 m. Also, a novel method of lithography was tried to make a 3D structure array by exposing a planar wafer to the generated parallel light and rotating an inclined x-y-z stage at an ultra-slow rate. An optimization of the 3D structure array can be achieved by simulating a 3D feed-horn MEMS antenna. The feasibility of fabricating both a 3D feed horn MEMS antenna and assembly of detector with 3D feed-horn MEMS antenna was demonstrated. As a result, it seems possible to use a 3D feed-horn-shaped MEMS antenna to improve microbolometer performance and to fabricate several optical microstructure applications.

Apparatus and method for frequency calibration between two radios

Abstract: Wireless devices transmit and receive radio signals based upon reference frequencies generated by crystal oscillators. If the reference frequencies of the transmitter and the receiver are different, the radio signals may not be received properly or may not be received at all. A measurement circuit measures the amount of error or signal corruption in the radio signals due to the reference frequency offset between the transmitter and the receiver. A frequency offset circuit generates an offset operating frequency in the transmitter or the receiver to align or calibrate the operating frequencies of the devices.

An optimized stepped profiled horn with low cross polarization for a 20/30 GHz DVB-RCS terminal

Abstract: A smooth-walled horn is often preferred over a corrugated horn due to easier and cheaper manufacturing By optimizing the profile of the horn it is possible to obtain low cross polarization over a broad bandwidth In this paper a very efficient method of profile definition, analysis and optimization for a stepped profile horn is described and applied to the design of a 20/30 GHz feed horn suited for a satellite broadcasting system with return link (DVB-RCS) The horn design is manufactured by plastic injection molding and metallization, as part of an ESA project

Multi-beam satellite antenna design

Abstract: This paper describes the antenna design of the multi-beam for communication satellites. The paper deals with a method to determine design core parameters of optimal antenna diameter, feed horn type and horn size, F/D, and the coordinate of offset horns, and the performance of the design results.

Experiments with small V-band waveguide reflector feeds

Abstract: The radiation patterns of simple rectangular waveguide feeds have been measured at V band. A low-cost test arrangement, operating in the far field but without any absorbers, is shown to give better than 0.5 dB repeatability and more than 30 dB of dynamic range. The general rules of waveguide-feed design for reflector antennas are applicable, but the tendency of narrow feed patterns is somewhat emphasized compared to observations in earlier work at C or X band. For horizontal polarization, the difference is 5 dB at 90/spl deg/ between WR-28 and WR-90 hardware. This is partly caused by an increase in the relative guide material thickness at shorter wavelengths. No clear connection between pattern widths of the two linear polarizations was observed if the guide height was increased, the largest momentary deviation being 3 dB for a rectangular 7.1 by 7.1 millimeter feed. Changes in the guide width had a monotone effect up to 3 dB at 90/spl deg/ offset. Very small feed aperture sizes, around /spl lambda//4 or less, did not show respective widening of 1 dB patterns, although such expected effects were visible at lower amplitude levels.

Parabolic Reflector Modelling Techniques with a Laterally Displaced Feed

Abstract: : This document looks at two techniques for modelling the radiation pattern of a parabolic reflector antenna. Both these methods use physical optics to determine the induced currents on the reflector due to the feed. The first method uses MATLAB's numerical integration routine to compute the far-field radiation pattern. The second method involves segmenting the reflector surface and approximating the amplitude and phase of the surface currents by a first degree polynomial. This approximation allows the integration to be performed analytically in closed-form. Three different reflector configurations are investigated including two configurations with a laterally displaced feed. Both these techniques yield accurate results but the latter technique had a significant improvement in computational efficiency.

Genetic Algorithm Optimization of Corrugated Horn Antennas

Abstract: The genetic algorithm (GA) optimization technique is applied to the optimization of a corrugated horn, designed as a feed for an offset reflector antenna. Two different approaches for optimization of corrugated horn antennas using GA are presented and a comparative study is performed among various designs