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作者 Bauregger, Frank Neil
書名 Novel anti-jam antennas for airborne GPS navigation
國際標準書號 0496517619
book jacket
說明 222 p
附註 Source: Dissertation Abstracts International, Volume: 64-09, Section: B, page: 4515
Adviser: Per K. Enge
Thesis (Ph.D.)--Stanford University, 2003
The Global Positioning System (GPS) is a worldwide passive radio navigation system that has found use in many civilian applications. The capabilities and performance of GPS are so impressive the FAA has mandated that GPS be incorporated into the next generation aircraft landing system. Despite the robustness of GPS, users may lose this service if strong radio frequency interference (RFI) is present at the airborne receiver antenna. Spurs from high power television and cellular phone transmitters are examples of unintentional RFI sources. Intentional RFI may arise from terrorist groups or simply from disgruntled individuals. Regardless of the source, RFI presents a potential danger to the aircraft and its passengers, especially during GPS guided approaches in poor visibility conditions. Unfortunately, there is no commonly available anti jam GPS antenna on the market today suitable for civil aviation
In this thesis, two antenna designs are proposed that serve as simple, small, and inexpensive anti-jam GPS antennas. The dielectric cavity antenna (DCA) makes use of an artificially soft surface to reduce the signal strength of ground-based jammers. To validate the concept of the DCA, a prototype antenna was constructed and tested. It was determined that the DCA provides modest (3--10 dB) protection against ground based jammers
The dual-patch reconfigurable antenna (DPRA) is an improved antenna design that employs two modes of operation. A wide-angle mode is selected for GPS navigation when no RFI is present, and allows reception of all visible GPS satellites. If RFI is present, the antenna may be placed in anti-jam mode, which rejects ground-based RFI and enhances signals from high elevation satellites. The DPRA is only slightly larger than conventional aviation GPS antennas, and may replace existing antennas with no modification to the fuselage. The DPRA has been built and tested in flight. Compared to a standard aviation patch antenna, the anti-jam mode attenuated a ground based simulated jammer by 15 dB. Because of this level of performance and the relative simplicity of the antenna, the DPRA is considered to be an elegant solution to the RFI problem for civilian aircraft using GPS/WAAS as the primary navigation system
School code: 0212
DDC
Host Item Dissertation Abstracts International 64-09B
主題 Engineering, Electronics and Electrical
0544
Alt Author Stanford University
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