Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 29 for “"reconfigurable antennas"”.
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Wideband reconfigurable antennas
… thesis concerns the combining of wideband and reconfigurable narrow band functionality into a single antenna. This concept may be useful in reducing size and to give flexibility to a wireless terminal to operate in several different modes. The approach also offers additional pre-filtering to …
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Energy storage in reconfigurable antennas
Despite their potential performance advantages, reconfigurable antennas have seen limited use in mobile devices. These complicated antennas can be challenging to design, especially when the structure is electrically small or mid-sized. With small elements, finite groundplanes, and switches or …
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RF-MEMS switches for reconfigurable antennas
Reconfigurable antennas are attractive for many military and commercial applications where it is required to have a single antenna that can be dynamically reconfigured to transmit or receive on multiple frequency bands and patterns. RF-MEMS is a promising technology that has the potential to …
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Physical layer encryption using fixed and reconfigurable antennas
… producing direction-dependent distortion using reconfigurable arrays is also shown. These two methods are combined and shown to be more secure and power-efficient than either in isolation. An analysis of secrecy rates through mutual information makes it possible to compare the performance of all …
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Design and analysis of pattern null reconfigurable antennas
… analysis, and measurement of pattern null reconfigurable antennas (NRAs). Unlike conventional pattern reconfigurable antennas, NRAs possess the ability to steer their pattern nulls, yielding interference rejection capabilities. While various NRAs exist, the current state of the art has two …
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Design, simulation, and analysis of reconfigurable antennas in GHz regime
… research focuses on the design and analysis of a reconfigurable antenna where the radiation pattern and its characteristics are altered in each operating state. Specifically three versions of the reconfigurable antenna have been designed, all made from the same materials. An industry standard …
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Neural network field programmable gate array (FPGA) controllers for reconfigurable antennas
Advantages of reconfigurable antennas are numerous, but limited by the method of controlling their configuration. This dissertation proposes to utilize the advantages of both Neural Networks (NN) and Field Programmable Gate Arrays (FPGAs) to overcome this dilemma. In this work, the methodology of …
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Design And Analysis Of Adaptive And Reconfigurable Antennas For Wireless Communication
… a tremendous increase in the number of antennas onboard, on the ground, and in orbital space. This places a burden due to the confined volume and limited weight requirements especially in space applications. The reconfigurable antenna is a promising and exciting new type of antenna, …
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Ultrawideband and Multi-state Reconfigurable Antennas with Sum and Difference Radiation Patterns
… The conventional forms of such pattern diversity antennas are generally working at a single or multiple narrowband frequencies and are designed for specific applications. Hence, generating sum and difference pattern diversity in wide range of frequencies requires the development of new pattern …
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Reconfigurable antennas based on microplasma as a time-varying dielectric or conductor
… chip, plasma photonic crystals, and microplasma antennas. Dynamic behaviors of microplasma packets were described using four different microchannel designs. An array of microplasma jets were used to demonstrate plasma photonic crystals exhibiting narrowband attenuation at 157 GHz. Using a …
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Investigation of mutual coupling effects on pattern null reconfigurable antennas in small adaptive arrays
… to modify the array pattern. Recently, pattern reconfigurable elements have been introduced into adaptive arrays, establishing a new form of array pattern control. Using a reconfigurable element model, null reconfigurability was shown to be particularly advantageous in small adaptive arrays. …
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Analysis, Implementation and Considerations for Liquid Crystals as a Reconfigurable Antennas Solution (LiCRAS) for Space
The space industry has predominantly relied on high gain reflector dish antenna apertures for performing communications, but is constantly investing in phase array antenna concepts to provide increased signal flexibility at reduced system costs in terms of finances and system resources. The problem …
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Design and Analysis of L-Band Reconfigurable Liquid-Metal Alloy Antennas
Efficient reconfigurable antennas are highly sought after in all communication applications for the ability to reduce space cost while maintaining the ability to control the frequency, gain, and polarization. The ability to control these parameters allows a single antenna to maximize its …
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Antenna element pattern reconfigurability in adaptive arrays
… the functional benefits of utilizing radiation reconfigurable antennas in an adaptive array setting. The work centers on arrays composed of a small number of widely spaced elements. Such array configurations (1) mitigate the effects of mutual coupling between reconfigurable elements, thereby …
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Active Antenna Bandwidth Control Using Reconfigurable Antenna Elements
Reconfigurable antennas represent a recent innovation in antenna design that changes from classical fixed-form, fixed-function antennas to modifiable structures that can be adapted to fit the requirements of a time varying system. Advances in microwave semiconductor processing technologies have …
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FPGA controlled reconfigurable antenna
At the present time, the advantages of reconfigurable antennas are numerous but limited by the method of controlling their configuration. This thesis proposes to utilize the advantages of Field Programmable Gate Arrays (FPGAs) to overcome this dilemma. Two experimental antennas are designed. The …
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A frequency reconfigurable slot antenna with a conductive microfluidic switching mechanism
Reconfigurable antennas have the potential to provide functionality to radio systems which will make them more robust and allow for much more efficient use of the electromagnetic spectrum when combined with cognitive radio. High power applications, however, cannot benefit from the advances made in …
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A frequency reconfigurable circularly polarized microstrip patch antenna using liquid metal microswitches
Reconfigurable antennas with adaptable frequency, pattern, and polarization offer flexibility and size reduction for wireless systems that must increasingly execute multiple missions with less volume. These antennas will also complement anticipated cognitive radio systems, which promise more …
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Analysis and design of reconfigurable multi-band stacked microstrip patch antennas (MSAs) for wireless applications
… is an increasing demand for smaller low-cost reconfigurable antennas that can be easily integrated with packaging structures. Reconfigurable Microstrip Patch Antennas (MSAs) received great attention in wireless communication systems due to their capability to vary their operating frequency, …
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Voltage control of electrical, optical and magnetic properties of materials by solid state ionic transport and electrochemical reactions
… paving the way towards applications such as reconfigurable electronics, reconfigurable antennas, active optical devices and energy efficient data storage. One promising way of achieving the controllability is through solid-state ionic transport and electrochemical reactions in thin film …
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