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1.
This letter presents a novel compact circularly polarized patch antenna for Global Positioning System/Global Navigation Satellite System (GPS/GLONASS) applications. The proposed antenna is composed of a simple square radiating patch fed by a capacitive dual‐feeder to increase the impedance bandwidth and a lumped element hybrid coupler to achieve the broadband characteristic of the axial ratio (AR). The realized antenna dimensions are 28 mm × 28 mm × 4 mm, which is the most compact size among the dual‐band GPS/GLONASS antennas reported to date. The measured results demonstrate that the proposed antenna has a gain of 2.5 dBi to 4.2 dBi and an AR of 0.41 dB to 1.51 dB over the GPS/GLONASS L1 band (1.575 GHz to 1.61 GHz). 相似文献
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Kyungjin Oh Bongjun Kim Jaehoon Choi 《Microwave and Wireless Components Letters, IEEE》2005,15(4):244-246
This letter presents the design of a novel integrated global positioning system (GPS)/remote keyless entry system (RKES)/personal communication system (PCS) antenna for vehicular application. The GPS (1575.42 /spl plusmn/ 1.023MHz) antenna element is a corner truncated microstrip patch providing circularly polarized broadside radiation pattern. The normal mode helical and monopole antennas are combined into one for RKES/PCS (447.7375MHz/1750-1870MHz) services. The proposed antenna satisfies all the bandwidth and gain requirements for GPS and RKES/PCS services. Good radiation characteristics for vehicular application have also been obtained. 相似文献
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Beggs J.H. Luebbers R.J. Ruth B.G. 《Antennas and Propagation, IEEE Transactions on》1993,41(9):1324-1327
The finite difference time domain (FDTD) technique is a popular method for analyzing electromagnetic scattering, radiation, and penetration problems. Several authors have recently applied the FDTD method to antenna radiation problems. To date, the antenna structures considered have been wire and conical monopole antennas, rectangular waveguides, pyramidal horn antennas, and microstrip antennas. Results from these analysis have been in the form of normalized field patterns and no results showing absolute gain have been presented. The article demonstrates the first staircased application of the FDTD method to the analysis of radiation from circular waveguides and other shaped-end radiators. Results of absolute gain versus angle are shown for a straight-cut circular waveguide and for two different shaped-end radiators. All FDTD analyses are full three-dimensional computations and are compared in each case with measured data 相似文献
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David Walsh David Lowe Stefano Capaccio Peter Daly Gill Richards Andy Wolfe Gordon Ingle Jim Lawson 《International Journal of Satellite Communications and Networking》1997,15(6):259-268
The use of GPS in aviation is now accepted, with extensive work being undertaken on the technological, precision and infrastructure requirements. Work has focused on providing a service that is able to operate continuously in all areas. GPS alone, however, is seen as being unable to satisfy the stringent requirements for some phases of flight. Of the many solutions proposed, the Russian GLONASS system has been regularly overlooked. The research described in this paper aims to present GLONASS as a realistic and proven augmentation to GPS for aircraft positioning. During October 1996 the Civil Aviation Authority (CAA) Institute of Satellite Navigation (ISN) at the University of Leeds, in conjunction with the National Air Traffic Services Ltd (NATS UK) and the Defence Evaluation and Research Agency (DERA), performed a series of landmark differential GPS/GLONASS flight tests using the DERA BAC 1–11 flying laboratory. A real-time differential system was constructed using two GPS/GLONASS receivers developed by the ISN and a C-band data link for the RTCA corrections. Integration onboard the aircraft with avionic sensors and flight management systems was achieved using the ARINC 429 protocol. Routes were designed and flown to evaluate the complete system over a variety of airborne dynamics for both en-route and approach situations. In total, over 16 h of flying time was recorded, including 30 runway approaches over nine flights. A thorough evaluation of the accuracy and integrity of the positioning system was performed. Emphasis was made in comparing the flight statistics with recognized Required Navigation Performance (RNP) figures. The paper describes in detail the project development and the results achieved. An analysis of the results, showing that aircraft positioning with GPS/GLONASS augmentation in a local area augmentation system (LAAS) scenario can achieve accuracies that are both comparable with GPS-alone solutions and can satisfy up to CAT II precision approach criteria, is presented. Results are also given for position propagation using velocities derived from GPS and GLONASS carrier phase measurements. © 1997 John Wiley & Sons, Ltd. 相似文献
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Study on the algorithms to correct and compensate for GLONASS signal deviation based on GNSS receiver 下载免费PDF全文
Hongbin Ma Wennian Xu Xinrui Liu Qiling Hu Xiang Huang 《International Journal of Communication Systems》2014,27(3):449-458
At present, because of the construction of the navigation and positioning systems such as the China BeiDou, the research on complex receivers has become very urgent and active. This paper reports on the compatibility of the combined GPS and GLONASS data processing system. Because of the Frequency Division Multiple Access (FDMA) access technique applied in GLONASS satellites, while different signals of GLONASS satellites pass through different parts of the Radio Frequency (RF), the group delay effect can appear. Especially, if the hardware design of the base station and rover station are different, the problem is more severe. Aimed at these issues, the reasons and conditions are studied and then the comprehensive correction methods of deviation are proposed such as: effective real‐time pseudorange and carrier phase deviation correction compensation; tracking GLONASS L2 signal; establishing a eceiver name database; base station providing the receiver name; rover station correcting deviation according to different base stations, and so on. Through the use of schemes and algorithms, the objective existence GLONASS deviation can be reduced, and the capacity of the GPS+GLONASS complex system can be improved. It is also demonstrated that if the base station receiver and rover are from different manufactures, the deviation from GLONASS pseudorange and carrier phase can lead to the failure of achieving centimeter level. With the algorithms, in all the applications and in any base station or networked system, the GPS+GLONASS complex system can exhibit the advantages over just GPS applied system both in positioning accuracy and positioning speed and other real‐time kinematic (RTK) positioning performance. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Graphic dependences allowing one to promptly estimate the basic parameters of microstrip antennas (MSAs) are obtained for two frequency zones of decimeter wavelength range with central frequencies of 1600 MHz and 406 MHz, in which the equipment of satellite positioning systems (GPS, GLONASS, GALILEO, BEIDOU) and the COSPAS-SARSAT emergency radio beacon equipment operate. The influence of cuts in the MSA radiator that form a slow-wave structure (SWS) on the resonance frequency and frequency bandwidth of the antenna are studied. A technique of designing an MSA with circularly polarized radiated waves and this SWS is proposed, and the double impedance frequency band expansion is reached. The obtained bandwidth data are compared with theoretical limit values calculated from specified relation-ships that take into account the dissipative loss in the radiator. The MSA radiation efficiency is estimated. 相似文献
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Peter Raby Peter Daly 《International Journal of Satellite Communications and Networking》1994,12(5):443-451
The presence of selective availability (SA) on GPS has led to a variety of proposals for mitigation of its effects, for example combining GPS with other sensors or by identifying and removing the SA using redundant information in the position solution. A further method for reducing the impact of SA is the combination of GPS and GLONASS measurements. GLONASS does not have any deliberate degradation. This paper describes several algorithms for combining GPS and GLONASS measurements in real time on a single receiver. There are two least squares solutions using the code phase measurements alone: one with the measurements from both systems weighted equally, and one with the measurements weighted by the covariance of the measurements. Kalman filters with no SA model, and first- and second-order models, using both the code and carrier phase to estimate user position and velocity, are also implemented. Two different adaptive schemes are compared which attempt to identify SA model parameters in real time. The algorithms are compared in terms of their positioning accuracy, computational overhead and robustness. A ten-channel GPS/GLONASS receiver developed at The University of Leeds is used to provide satellite data for the evaluation of the different methods. 相似文献
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Stuart Riley Peter Daly 《International Journal of Satellite Communications and Networking》1994,12(5):453-462
The transmission of satellite signals at two widely spaced frequencies allows correction of the ionospheric delay. Both GPS and GLONASS transmit such signals, and to date there have been no published dual frequency GLONASS studies. This paper shows the fundamental accuracy of the Leeds University multichannel GPS/GLONASS receiver. Details are then given of the processing methods that have been used to obtain the ionospheric group delay using GLONASS L1 and L2 P-code measurements. Examples of the measured delay are provided and compared with the GPS model. Navigation results are shown using the P-code phase at L1 only and with a combination of the L1 and L2 measurements. An analysis of the accuracy of the P-code pseudorange and navigation capability is presented. 相似文献
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Chi-Fang Huang Li Chen 《Electronics letters》2002,38(20):1162-1163
A design method is presented for a printed-on-display (POD) antenna, which is intended to replace the traditional antennas installed on diverse wireless mobile terminals which have both an antenna and an electronic display. The POD antenna is composed of printed radiators which are made of a material being both electrically conductive and optically transparent 相似文献
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Gary Brodin Peter Daly 《International Journal of Satellite Communications and Networking》1997,15(1):25-34
It is well known that multipath represents a major error source in differential GNSS positioning. Errors produced are unique to each antenna position and so are uncorrelated between the reference station and the mobile receiver. Reduction techniques, such as narrow correlator spacing1 and the multipath estimating delay lock loop (MEDLL)2 have improved the situation. However, reflected signals emanating close to the antenna are not reduced by either technique. Carrier multipath is a particular problem because short delay multipath signals cause maximum carrier errors. This study describes the analysis that has been carried out into code and carrier tracking in the presence of multipath. Code tracking in this situation produces a non-zero mean error,3 and the source of this bias has been investigated. Code and carrier multipath errors of the global orbiting navigation satellite system (GLONASS) have been compared with those of the global positioning system (GPS). The effects of pre-correlation filtering on code and carrier multipath errors have been determined using data from a measured correlation function. The multipath fading bandwidth is also discussed, and fast and slow fading effects are presented. A comparison has been made of the performance of typical coherent and non-coherent code discriminators in the presence of multipath. The performance of the GPS and GLONASS P code signals have been determined with respect to code and carrier multipath errors. © 1997 by John Wiley & Sons, Ltd. 相似文献
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为了提高 GPS/GLONASS/BDS三系统组合定位的稳定性和精确度,研究加权最小二乘定位中的定权方法。提出一种结合高度角先验定权和验后方差估计的定权方法,利用多系统兼容接收机实测数据进行仿真验证。结果表明,相较于传统的最小二乘法,该定权方法可以明显改善多系统组合定位的精确度,且具有很好的抗差性能,提高了定位结果的稳定性,可应用于多系统兼容接收机组合定位解算中。 相似文献
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Miniature Interferometer Terminals for Earth Surveying: Ambiguity And Multipath with Global Positioning System 总被引:9,自引:0,他引:9
Counselman Charles C. Gourevitch Sergei A. 《Geoscience and Remote Sensing, IEEE Transactions on》1981,(4):244-252
With the recent launching of several satellites of the global positioning system (GPS), a variety of schemes based on radio interferometry have been proposed for the accurate determination of relative positions of receiving terminals on the ground. Provided that the integer-cycle ambiguities of the interferometric phase observations can be correctly resolved, the baseline vector extending from the antenna of one terminal to that of another should be determinable with uncertainty much smaller than the 19-cm wavelength of the GPS transmissions. We propose a method of ambiguity resolution that is suitable for observations made with antennas of low directive gain. Such antennas are compact, but the feasibility of their use has been questioned because observations with them are susceptible to multipath interference. For short-baseline interferometric observations of GPS our method yields correct ambiguity resolution despite severe multipath interference and significant sky blockage, even when instability of the frequency standards governing the separate receiving terminals limits the time span of coherent integration to five minutes. 相似文献
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As commercial needs have expanded the functions of the wireless cellular handsets, multiantenna development in one handset has become more and more common. This paper addresses a multiantenna solution for the wireless handset application. A planar inverted "F" antenna (PIFA) was designed as the main antenna of the handset to cover the 800 MHz band (824 MHz-894 MHz) and the 1900 MHz band (1850 MHz-1990 MHz). A side-mounted inverted "F" antenna (IFA) was designed as the 1575.42 MHz global positioning system (GPS) antenna. The location of the feed/ground pins of both antennas affected not only the total antenna efficiency, but also the polarization of the GPS IFA. The length of the GPS IFA affected the isolation between the two antennas and the specific absorption rate (SAR) of the PIFA at the 1900 MHz band. A three-dimensional efficiency measurement of the prototypes in both free space and against-head position will be presented. Measurement of SAR and its distribution will also be presented to demonstrate the impact of the IFA on the near field of the PIFA. 相似文献
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《Antennas and Propagation, IEEE Transactions on》2008,56(7):1860-1866
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Corrugated horn antennas offer many advantages compared with other waveguide radiators. A major disadvantage which is inherent
with the design of a corrugated horn is the fact that slow-wave modes may exist within the horn antenna. In this paper far-field
measurements of a W-band horn antenna are presented. The experimental data is compared with simulated data to confirm the
presence of slow-wave modes. The analysis is completed by determining the waist, the gaussicity and the phase center location
of both the experimental and model data. Finally a redesign approach is proposed which suppresses the slow-wave modes and
therefore increases the usable bandwidth of the horn antenna. 相似文献
20.
Padros N. Ortigosa J.I. Baker J. Iskander M.F. Thornberg B. 《Antennas and Propagation, IEEE Transactions on》1997,45(4):698-706
The FAA decision allowing the use of the global positioning system (GPS) as a radio navigation and landing help system in the United States commercial airports boosts the need for a high-performance GPS receiver which provides the demanded precision. The design of the receiving antenna is one of the most important parts in the design process, as it has to face significant challenges including uniform coverage of all satellites and the rejection of the multipath signals. The rejection of the multipath signals is accomplished by specifying restrictive criteria to the GPS antenna. This includes a high rejection of the cross-polarized signals and a radiation pattern with a sharp slope for low-elevation angles; that is, near the horizon. The feasibility of using different types of antennas to satisfy restrictive criteria such as dual-frequency coverage (L1 and L2 frequencies), -15 dB cross-polarization rejection, and a beamwidth of more than 130° is discussed. The antenna designs examined in this study include patch antennas, helical antennas, and conical spiral antennas. Two different receiver designs were also examined including a single-antenna system with a hemispherical coverage and an antenna array which may provide independent sectoral coverage or the desired beamwidth. It is shown that a design based on a conical spiral antenna backed with absorbing material may be used to satisfy all the desired specifications. This result was confirmed experimentally 相似文献