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.
Results
Showing 1 to 20 of 50 for “"Electrically Small"”.
-
Fast Algorithm for Electrically Small Inhomogeneous Medium Structures
With the above accomplishments, electrically small composite structures involving lossless or lossy materials can be solved with O( N) computational cost.
-
Tunable electrically small antenna for next generation ionospheric heating
An efficient, metamaterial inspired electrically small antenna with the capability of frequency reconfiguration is evaluated for potential future use in Transportable Ionospheric Heating. Consisting of a Small Loop Antenna (SLA) inductively coupled to a Capacitively Loaded Loop (CLL) this design …
-
Design and Analysis of Circularly Polarized Electrically Small Antennas
… on two novel antenna designs. One design is an electrically small, circularly polarized planar cross dipole and the other design is a compact circularly polarized log-periodic dipole array. Both antennas are designed in simulation software with the intent for prototype fabrication for …
-
Electrically-Small Antenna Performance Enhancement for Near-Field Detuning Environments
… enhancement of low-profile omnidirectional, electrically-small antennas has evolved from the design and construction of AM transmitter towers eighty years ago to current market demand for battery-powered personal communication devices. Electrically-small antenna theory developed with …
-
Analysis and design of electrically small, circularly polarized cylindrical microstrip antennas
Small unmanned aerial system (UAS) and smart missile and munitions platforms rely on GPS for accurate position, velocity and time (PVT) information. These platforms have significant aerodynamic and space constraints that require innovative conformal GPS antenna solutions. Microstrip antennas are …
-
Characteristic Modes for Impedance Matching and Broadbanding of Electrically Small Antennas
Antennas smaller than a quarter wavelength are fundamentally constrained in a variety of ways. One of the more problematic limitations is that the antenna's bandwidth declines sharply as the size of the antenna decreases. Myriad studies have sought antennas that perform close to the fundamental …
-
Modeling electrically small apertures using the finite difference-time domain method
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.
-
An electrically small multi-port loop antenna for direction of arrival estimation
… large. In order to reduce the size of the array, electrically small elements may be used. Furthermore, a reduction in the number of necessary elements can help to accomplish the goal of miniaturization. The proposed antenna uses both of these methods, a reduction in size and a reduction in the …
-
Investigation of electrically small antennas designed for directive radiation from transient signaling
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01
-
Development of an Electrically Small Vivaldi Antenna: The CReSIS Aerial Vivaldi (CAV-A)
… Contrary to convention, the CAV-A is an electrically small antenna, with an antenna width and length on the order of a quarter free-space wavelength at the lowest frequency of operation.
-
Design and analysis of direction-of-arrival estimation systems using electrically small antenna arrays
… whose interelement phase di erence is very small or even negligible. Traditionally, direction- nding systems have been quite large to ensure a re- solvable phase delay between elements. Since the direction- nding arrays presented here are much less reliant on interelement phase delay, their …
-
Design and analysis of an electrically small inductively loaded sector antenna for frequency reconfiguration using varactor diodes
… to address this issue, an inductively loaded, electrically small, frequency reconfigurable, sector antenna that covers most consumer frequency bands has been developed. This thesis details the design and characterization of the antenna element, which tunes the GSM 900, GSM 1800, 3G, WiFi, and …
-
The utilisation of commercial off the shelf carbon nanotube fibre in individual metamaterial antennas to enable a reduction in operating frequencies
… of metamaterial research, can be used to produce electrically small antennasWe find that basic improvements to metamaterial antenna designs enable low broadcast frequencies utilising standard bulk metals. However, the increased surface area of the carbon nanotube fibre enables further reductions …
-
Investigation of Low Profile Antenna Designs for Use in Hand-Held Radios
… radios must be compact and unobtrusive. Electrically small and low-profile antennas experience high input reactance, low input resistance, and low radiation efficiency.Further degradation of radiation efficiency occurs in hand-held radios due to size-reduced ground planes, losses within …
-
Energy storage in reconfigurable antennas
… to design, especially when the structure is electrically small or mid-sized. With small elements, finite groundplanes, and switches or reactive tuning mechanisms, performance of these reconfigurable antennas is often strongly influenced by energy storage effects. Many antenna types achieve …
-
A Nonlinear Technique for Bandwidth Improvement in Narrowband Antennas
Electrically small, low profile antennas have become the new frontier in wireless communication research. With the pressure to miniaturize wireless communication devices, engineers are turning to small low profile antennas as a way to reduce their antennas and hence their devices. Ideally, one …
-
Near-Field Focusing Phased Array for Hyperthermia Application
A conventional hyperthermia applicator is an electrically small antenna which produces a divergent beam. In this thesis, we propose a focused applicator made of phased arrays. The advantages of an array applicator are (i) smaller input power and less surface heating for achieving the same field …
-
Time-varying Small Antennas for Wideband Applications
… to achieve a high-rate data transmission through electrically small antennas. However, the overall transmission bandwidth is limited by the antenna size. As a well-known physical limitation, maximum achievable bandwidth of a small antenna is governed by the fundamental limit which defines a lower …
-
Time-Variant Components to Improve Bandwidth and Noise Performance of Antennas
… design a low-noise active matching circuit for electrically small antennas in our second design. Using Chu's limit and the Bode-Fano bound, we show a trade-off between the noise and bandwidth of the electrically small antennas. In particular, to make the small antenna wideband, one needs to …
-
Miniaturized, Directional Antennas For Wireless Power Transfer
… transfer. Next, two miniaturized antennas, an electrically small, circular polarized parasitic array antenna, and a miniaturized circularly polarized 2x2 array antenna, are introduced for possible use as wireless power reception antennas. Each antenna utilizes top-loading and multiple folding …
Page 1 of 3