Beacon Antenna Research Articles

Design of Octagon Monopole Dual Frequency Indoor Positioning Beacon Antenna

Aiming at the antenna performance requirements of Bluetooth and UWB indoor positioning system, an octagon monopole dual-frequency indoor positioning beacon antenna is made. The antenna can operate in both UWB and Bluetooth communication bands. The antenna performance is improved by grooving the antenna and adding metal strips. The use of curved and gradual structure feeders also makes the antenna get better bandwidth performance.

Compact high-gain composite horn antenna for space-borne beacon application

ABSTRACTThe growing interest in higher capacity communications satellite necessitates the development of compact and lightweight other antennas (such as beacon horn antenna) at Earth-viewing deck due to crowded accommodation and weight limitation. In this article, we describe an innovative and compact high-gain composite horn antenna for space-borne beacon application. We have designed, manufactured and measured beacon horn antenna operating from 10.7 GHz to 12.5 GHz. The beacon horn antenna is devised by combining stepped section at input, axial corrugated in mid and finally radial corrugated sections. This engineered multiple sections provide extra flexibility of optimisation, leading to high edge of coverage (EoC) gain for Indian mainland, Lakshadweep Islands and Andaman & Nicobar Islands. The radial corrugated section is specially profiled using multi-profile subsections. The mode-matching technique (MMT)-based software CHAMP and ‘minimax optimiser’ have been used to analyse and optimise the Beacon horn antenna. Manufacturing of the horn using a turning machine over aluminium alloy helps to reduce its cost. Characterisation of the beacon antenna confirm predicted electrical results (return loss> 17 dB, cross-polarisation discrimination < −40 dB, EoC gain > 24 dB). The Accommodation of the Ku-Beacon antenna on spacecraft is discussed with help of its near field from the scattering point of view and its tilt.

Ultra-small Marker Beacon Antenna with a Wide Frequency Tuneable Capacitive Plate

In this paper, an ultra-small marker beacon antenna operated in the VHF-band is proposed. This antenna has a modified linear IFA structure with a lumped capacitor and a capacitive plate for frequency tuning and impedance matching. The capacitive plate is directly connected to the end of a linear radiator and is separated from the antenna ground by 1 mm. The main operating frequency is mainly controlled by the size and dielectric constant of the capacitive plate. The lumped capacitor is useful for fine frequency tuning. Using the proposed structure, an ultra-small marker beacon antenna can be realized with a length of 0.04 λ0.

Beacon antenna for harsh environment

A beacon antenna is proposed using in beacon device of digital flight data recorder for harsh environment. The antenna has a simple structure and works at the center frequency of 2.645GHz. Its fabrication employs a low-cost and planar printed technique. The antenna contains a main patch and 3 derivative elements, act as radiators. The proposed antenna is designed by employing the genetic algorithm (GA). A prototype antenna is fabricated and measured. The measurement results agree with the simulation data and show that this antenna possesses encouraging features. For example, it has a well-formed radiation pattern with a high gain level of 6dBi, the antenna achieves an impedance bandwidth of 2.3% of the center frequency (2.613GHz ∼2.675GHz) for S11<−10dB and 3dB gain-drop bandwidth of 95°.

Beacon Antenna Controller based on Synchronous Satellite

In order to improve the communication efficiency between beacon antennas of flight recorder and the synchronous satellite, a beacon antenna controller based on synchronous satellite has been designed. The optimal communication antenna selection is realized by calculating the angle between the aircraft and the synchronous satellite using Global Positioning System (GPS) position information and flight attitude. The simulation and experimental results show that reliable automatic switch of the antenna can be realized by the antenna controller which can accurately calculate the angle between the aircraft and the satellite after receiving the position and posture information.

Rattlesnake Antenna System [Education Column

A rattlesnake antenna system (RAS), inspired by the hunting behavior of rattlesnakes, is proposed. It can automatically align the main beams of the directive antennas at both the transmitting (Tx) and receiving (Rx) sites, and then perform distant data transmission/reception. Each of the transmitting and receiving sites consists of an antenna module, an RF module, a state-control module, a motor-driver module, and a stepper motor. The functionalities, design, and assembly of these modules are detailed in this paper. The antenna module is composed of three square patch-antenna elements, and functions as a beacon antenna, two sensing antennas, and a high-gain transmitting or receiving antenna, depending on the states of the associated switches. The beacon antenna at one site, having a wider angular coverage, provides a beacon signal for the two sensing antennas at the other site. Connecting the sensing antennas to power detectors and a difference circuit, the auto-aiming subsystem can thus locate the direction of the other site, and trigger the stepper motor to rotate accordingly. After aligning the two sites with each other, the antenna module acts as a high-gain antenna for high-quality and long-range data transmission/reception. The detailed design concept and operational principles of the antenna modules, and the operational procedures of the rattlesnake antenna system, are also presented. A prototype system was built and tested, and the auto-aiming and long-range communication functionalities were successfully demonstrated.

A DORIS determination of the absolute velocities of the Sorsdal and Mellor glaciers in Antarctica

The Lambert–Amery System is the largest glacier–ice shelf system in East Antarctica, draining a significant portion of the ice sheet. Variation in ice sheet discharge from Antarctica or Greenland has an impact on the rate of change in global mean sea level; which is a manifestation of climate change. In conjunction with a measure of ice thickness change, ice sheet discharge can be monitored by determining the absolute velocities of these glaciers. In order to demonstrate the capability of the DORIS system to determine glacier velocities, Geoscience Australia undertook a Pilot Project under the auspices of the International DORIS Service. A DORIS beacon was deployed on the Sorsdal (November 2001 – January 2002 and November 2003 – January 2004) and Mellor (December 2002 – January 2003) glaciers. The DORIS data, transmitted from the autonomously operating ground beacon for each satellite pass, were stored in the receiver on-board the satellite and later downlinked to the DORIS control centres for processing. This paper describes the campaigns that were conducted at the Sorsdal and Mellor glaciers, the data processing standards for modelling the Doppler measurements, precise orbit determination of the satellites using the data from the globally distributed DORIS network, tracking station position and reference frame modelling, the point positioning mode employed for determining the position and velocities of the transmitting beacon antennas located on the glaciers and provides the velocity estimates that have been determined from the analysis of these tracking data. For the Sorsdal 2001/2002 campaign, using SPOT-4 data only, the measured effective horizontal ice motion was estimated to be 30 ± 0.4 cm/day (azimuth of N246°E ± 0.1°). The inferred velocities for the Sorsdal 2003/2004 campaign, using SPOT-4 and SPOT-5 data, was 5.7 ± 0.8 cm/day (azimuth of N264°E ± 7.5°) for the first eight days and 11.4 ± 1.4 cm/day (azimuth of N241°E ± 1.5°) for the subsequent 21 days. There was a noted decrease in the inferred velocities between the beginning and the end of the observing period. A sub-division of the latter 21 day observing period into three segments showed a decrease in 2D velocity from 18.3 ± 0.7 to 11.2 ± 0.7 cm/day and then to 7.4 ± 0.9 cm/day for the first, second and third segments, respectively. In comparison, a GPS derived velocity over the time-span of the 2001/2002 Sorsdal campaign gave a mean ice flow rate of 31 cm/day. The GPS velocity was derived from two daily position estimates 65 days apart. The DORIS determination from 26 days of continuous SPOT-4 and SPOT-5 data compared well with the GPS derived velocity. For the 2002/2003 Mellor glacier campaign, using SPOT-4 and SPOT-5 data, the estimated average ice velocity was 104 ± 25 cm/day (azimuth of N33°E ± 0.1°); which compared well with an InSAR derived velocity of between 110 and 137 cm/day. The point positioning technique as implemented in this study was further validated and assessed by replicating the computational process to determine the position and velocity of the permanent International DORIS Service site at Terre Adélie, Antarctica. Through these experiments, it has been successfully demonstrated that the DORIS system is capable of determining the velocities of glaciers with an accuracy of a few cm/day over a period of several weeks; operating in remote regions in an autonomous mode. With an increasing number of DORIS-equipped satellites and multiple daily passes, it has the potential to measure glacial velocities at a high temporal resolution (sub-daily).

In-flight experiment for combined planar antennas and solar cells (SOLANT)

An in-flight experiment to validate advanced solar antenna structures (SOLANT) in space is presented. Two different antennas have been designed and manufactured, one for global positioning system (GPS) reception and one for S-band beacon transmission. Both units use slot aperture radiators embedded in identical mechanical structures. The GPS antenna has been designed to generate an omni-directional radiation pattern with right-handed circular polarisation thus fulfilling NavStar specifications. The S-band beacon antenna is based on a four-element circularly polarised array providing 6 dBic of gain. These antennas are integrated within two solar panels, which form the upper layer of the antenna structure. The two panels are identical, make use of gallium arsenide (GaAs) solar cells arranged in two strings and provide a peak power of 10 W each. The SOLANTs were launched, fixed to a Cosmos payload adapter and remained operative for 2 years, well beyond their expected lifetime. This study summarises the design and performance tests performed prior the launch and during the orbital operation.

Multipath Mitigation under Forest Canopies: A Choke Ring Antenna Solution

Abstract Evaluating the accuracy of global positioning system (GPS) receivers in applications under forest canopies has become an area of increasing interest. Reducing the error experienced by multipath present under forested conditions has also been a significant concern. We present results of assessing a choke ring antenna solution to the reduction of multipath effects under forest canopies. This system serves to increase the accuracy of positional fixes as well as provide a baseline for assessing multipath effects. We assessed these by comparing results to data collected by separate antenna configurations (yet same receiver) on varying slope positions and canopy conditions. Using a choke ring antenna, we found horizontal position accuracy of differentially corrected data to range from 0.32 to 0.88 m root mean square error reported at 95% confidence across a topographic gradient during leaf-on conditions. Under leaf-off conditions the horizontal position accuracy ranged from 0.35 to 0.69 m. Similar differentially corrected data collected using a standard beacon antenna showed that horizontal position accuracy ranged from 4.9 to 6.1 m during leaf-on conditions and from 3.3 to 5.8 m during leaf-off conditions. When sampled, the data from the two systems were collected within 1 minute of each other; thus, we assume a very similar plane and satellite arrangement. Coupled with topographic factors, a minimum multipath error effect could be determined for this receiver for given site conditions by taking the difference between the two levels of error.

Using Low-Power Radios for Mobile Robots Navigation

Abstract This paper addresses the general field of mobile robots navigation within fixed sensor networks. We focus on an innovative navigation for indoor environments that is based on Radio-Frequency (RF) communication and its Received Signal Strength (RSS). We propose two methods for guiding a robot towards an RF beacon using low-power radios, namely the oblivious and the iterative methods. While the former has negligeable resource requirements, the latter requires more memory, processing power and odometry but it presents a substantially improved performance. We noticed that noisy RSS measurements are the main obstacle in our problem, since the noise incurs great ambiguity in the RSS gradient climbing. Thus, we introduce antenna diversity in the beacon and omnidirectional antenna with shielding plane in the robot to reduce multi-path phenomena and provide a better relationship between robot-beacon distance and RSS. The efficiency of these techniques as well as the performance of the oblivious and iterative methods are evaluated via simulations and practical experiments with an autonomous mobile robot. The results validate the methods and confirm the viability of RSS-based navigation.

電気炉ダストを再溶解したスラグの電磁波吸収舗装への適用

The electronic toll collection (ETC) and the dedicated short range communication (DSRC) in intelligent transport systems (ITS) are realized. To improve electromagnetic environment of ITS beacon antenna, a wave absorbing pavement material consists of a carbon fiber has been developed. However, the oblique incidence characteristic of the pavement material that has been developed for the ETC is not enough to use for ETC and DSRC. Therefore, this research group is developing the wave absorbing pavement that mixed with DSM (Daido Special Recycling Process for Dust and Slag Melting) slag into asphalt. On the other hand, there was a base concrete layer under two asphalt layers. To design the wave absorbing pavement, we calculated with consideration of the impedance of the base concrete layer. In this paper, the relative complex permeability and permittivity of the pavement material were measured by the free space methods and the waveguide method. And the impedance of the base concrete layer was measured by the free space method. Then, the wave absorbing pavement of the oblique incidence characteristic was designed using the obtained material constants.

ＥＴＣ用電磁波吸収舗装材の開発

The electronic toll collection (ETC) and the dedicated short range communication (DSRC) in intelligent transport systems (ITS) are materialized. To improve electromagnetic environment of ITS beacon antenna, a wave absorber pavement material consists of a carbon fiber has been developed. However, the oblique incidence characteristic of the pavement material that has been developed for the ETC is not enough to use for ETC and DSRC. Therefore, this research group is developing the wave absorber pavement that mixed soft magnetic metal powder into asphalt. In this report, the relative complex permeability and permittivity of the pavement material were measured by the free space methods and the waveguide method. Then, the wave absorber pavement of the excellent oblique incidence characteristic was designed using the obtained material constant. The calculated result of oblique incidence characteristics showed good agreement with measured one in their tendency.

Mobile communications higher‐order‐mode microstrip antennas for road vehicle communications

AbstractCar antennas for road vehicle communications systems should be able to receive constantly the signals of beacon antennas at positions from just below the beacon antenna to a great distance along the road. In this paper, we restrict the discussion to the case of microstrip antennas and investigate what kind of patch shape is suitable for car antennas used in road vehicle communications systems. As a measure for evaluating the receiving power level, we define and use the “effective directivity,” which takes account of the distance between the beacon antenna and car antenna and the relative arrangement of both antennas. This effective directivity represents the effective received electric field intensity. We examine various patch shapes from the viewpoint that the desirable ones have constant effective directivity irrespective of car position. As a result, three types of simple‐structure higher‐order‐mode microstrip antennas are proposed. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(11): 54–60, 2001

ACTS propagation experiment: experiment design, calibration, and data preparation and archival

The National Aeronautics and Space Administration Advanced Communications Technology Satellite (ACTS) propagation experiment was designed to obtain slant-path attenuation statistics for locations within the United States and Canada for use in the design of low-margin Ka-band satellite communication systems. Experimenters at seven different locations have collected propagation data for move than two years. The propagation terminals used for the experiment were identical. A single preprocessing program was used by the experimenters to provide for automatic calibration, generation of attenuation histograms, and data archival. In this paper, the calibration procedures are described mid estimates given for measurement accuracy. ACTS provided beacons at 20.2 and 27.5 GHz for use in making attenuation measurements. In addition to the beacon receivers, each ACTS propagation terminal has two total power radiometers with center frequencies at the beacon frequencies. The radiometers are used to establish the beacon signal reference levels needed for calculating beacon attenuation values. For the combined radiometer and beacon measurement system, the attenuation measurement error was less than a maximum of 1.0 dB and was generally less than 0.3 dB. The dynamic range for attenuation measurement varied from site to site depending on location relative to the peak of the satellite beacon antenna pattern. For locations within the continental United States, the dynamic range was better than 20 dB.

Conformal antenna synthesis using spherical harmonic wavefunctions

A new antenna-synthesis method is described that allows the antenna surface geometry to be arbitrarily specified and the radiating current distributions to be computed directly from the radiation patterns, which can be quite general and have any type of polarisation: this latter process makes the synthesis procedure nonunique, but is of great practical value since phase information is not required. Illustrative examples based on rotational symmetry are given to show the effect of all the various sources of controllable error, and useful information is also extracted about the formulation of active conformal arrays of small closely spaced noninteracting radiating elements; in particular, a means of optimising a conformal beacon antenna and creating a wide bandwidth supergain system by utilising the closely spaced driven array principle is discussed.

Evaluation of lateral displacement of SLS antennas

A detailed analysis is made of a laterally displaced interrogator sidelobe suppression (SLS) radar beacon antenna system. This method is recommended as a very economical solution to the FAA requirement for installing interrogator SLS capability at operating beacon systems where no provision had been made for interrogator SLS. The analysis was verified by an actual field test at a joint use (Department of Defense/Federal Aviation Agency) radar site at Sault Ste. Marie, Mich. Sidelobe suppression was practically complete and neither time displacement nor blockage was discernible as predicted by the analysis.

An electronically scanned beacon antenna

An electronically scanned cylindrical array having a minimum number of active devices has been designed. A saving of over 3 to 1 in diode elements as compared to conventional approaches has been achieved. In addition to providing instantaneous positioning to any azimuth direction, a constant azimuth beamwidth for an elevation fan beam has been realized. Extremely low azimuth sidelobes are obtained, and a straightforward synthesis procedure can provide elevation aperture designs to meet typical elevation pattern requirements. A modified Myer geodesic lens combined with a diode sequencing switch for coarse steering and a phased matrix feed for fine steering form the basis of the system. Sum and difference patterns show virtually no variation with scan or elevation angle and an omni-pattern is also available. Detailed pattern calculations as well as measured data on prototypes of key elements of the system are presented to verify the feasibility of the approach.

Correction [to "An improved ground beacon antenna"

Correction [to "An improved ground beacon antenna"

An Improved Ground Beacon Antenna

An electromechanical scanning antenna technique is proposed to provide improved TACAN ground-beacon performance over the full 960-to 1215-Mc band.A radially symmetric, shaped-beam reflector is illuminated by an off-set, radial-pillbox horn. The horn is driven by a radial transmission line which contains a central radiator. Parasitic elements are arranged in dielectric rings positioned concentrically with the central radiator. The rings are rotated uniformly about the center line to generate an amplitude-modulated, omnidirectional azimuth pattern. The complex response of the elements controls the percentage modulation, while the geometry of the reflector and its feed independently control the shape of the elevation pattern. The antenna generates uniform azimuth modulation over the elevation angles of interest.

Radar Beacons for IRBM/ICBM

This paper summarizes problems which confront engineers who are responsible for the design of radar beacons and beacon antennas used in IRBM and ICBM test vehicles. The most important factors which affect compatibility between the beacon and tracking radars at the test range are enumerated. Cited also are several design areas which should be correlated with the test range prior to finalization of beacon design criteria.