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Conformal Microstrip GPS Antenna for Missile ApplicationFischer, Andrew Cassidy 01 June 2011 (has links)
Optimal missile guidance and flight performance require accurate and continuously updated in-flight coordinate data. The Global Positioning System (GPS) is used for this positional awareness. However, due to missile rotation and orientation variations during flight, GPS signal reception using traditional antennas may be intermittent. To remain cost competitive, Stellar Exploration Inc. is developing a low-cost omnidirectional GPS antenna for guided missile prototypes.
In this thesis, existing products and design techniques are examined, design constraints for supersonic missile applications are investigated, and corresponding performance goals are established. A conformal microstrip patch antenna is developed and simulated in Agilent’s Advanced Design System (ADS). The resulting antenna is constructed and characterized. Prototype testing verifies that the antenna maintains GPS signal lock regardless of orientation. The final cost is significantly lower than existing conformal products.
A second revision investigates enhanced modeling, dimensional reductions (via increased dielectric constant), and radome construction. Performance is compared to first revision antenna results and differences are examined. Suggestions for further revisions are discussed.
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Development of automobile antenna design and optimization for FM/GPS/SDARS applicationsKim, Yongjin 01 October 2003 (has links)
No description available.
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Analytical Techniques and Operational Perspectives for a Spherical Inverted-F AntennaRolando, David Lee 2010 December 1900 (has links)
The spherical inverted-F antenna (SIFA) is a relatively new conformal antenna
design that consists of a microstrip patch resonator on a spherical ground. The SIFA
resembles a planar inverted-F antenna (PIFA) that has been conformally recessed onto a
sphere. The basic design, simulation, and fabrication of a SIFA were recently reported.
The aim of this thesis is to provide a three-fold improvement to the study of the SIFA:
the fabrication of a dielectric-coated SIFA, a new analytical model based on the cavity
method, and the analysis of a randomly oriented SIFA’s operation in a remote
networking scenario.
A key improvement to the basic SIFA design is the addition of a lossy dielectric
coating to the outside of the sphere for purposes of impedance stability, bandwidth
control, and physical ruggedization. The first contribution of this thesis is the fabrication
of such a dielectric-coated SIFA. Two antennas are fabricated: a coated SIFA operating
at 400 MHz, and an uncoated SIFA operating at 1 GHz for comparison. Both SIFAs are
constructed of foam and copper tape; the coating is comprised of silicone rubber and carbon fiber. The fabricated designs perform with reasonable agreement to
corresponding simulations, providing a basic proof of concept for the coated SIFA.
The SIFA was previously studied analytically using a transmission line model.
The second task of this thesis is to present a new model using the cavity method, as
employed in microstrip patches. The SIFA cavity model uses a curvilinear coordinate
system appropriate to the antenna’s unique geometry and is able to predict the antenna’s
performance more accurately than the transmission line model.
The final portion of this thesis examines the performance of the SIFA in a remote
network scenario. Specifically, a line-of-sight link between two SIFAs operating in the
presence of a lossy dielectric ground is simulated assuming that each SIFA is randomly
oriented above the ground. This analysis is performed for both uncoated and coated
SIFAs. A statistical analysis of the impedance match, efficiency, and power transfer
between these antennas for all possible orientations is presented that demonstrates a
design tradeoff between efficiency and predictability.
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A UTD ray description for the collective fields radiated by large antenna phased arrays on a smooth convex surfaceJanpugdee, Panuwat 12 September 2006 (has links)
No description available.
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Analysis And Design Of Cylindrically Conformal Microstrip AntennasTasoglu, Ali Ozgur 01 July 2011 (has links) (PDF)
Cylindrically conformal microstrip antennas are investigated. Two different structures, namely proximity coupled and E-shaped microstrip antennas are analyzed and information about the design parameters is obtained by means of parametric study. With these structures, cylindrical arrays, having omnidirectional radiation in the circumferential plane of the cylinder, are designed. Proximity coupled cylindrical arrays operate in the 2.3-2.4 GHz aeronautical telemetry band with approximately 4% bandwidth. On the other hand, more than 30% bandwidth is obtained by E-Shaped cylindrical array
antenna structure, which also includes the commercial telemetry band. In order to verify the simulation method, a fabricated antenna in literature is simulated and acceptable agreement with simulation and fabrication results obtained.
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Design Methodology for Wideband Electrically Small Antennas (ESA) Based on the Theory of Characteristic Modes (CM)Obeidat, Khaled Ahmad 26 August 2010 (has links)
No description available.
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