Radiation Efficiency improvement of miniaturized microstrip antenna is studied in this thesis. It is shown that, the loss reduction in miniaturized Microstrip Antenna can be achieved through two possible ways. The first is by modifying the materials used for building the antenna, and the second method is by increasing the radiation conductance of the antenna. Material modification at nano/micro scale by replacing conductors with Metallo-Dielectric one dimensional medium for applications in loss reduction is investigated first. It is shown by the Transfer Matrix Method and using simulations that, for a one dimensional medium replacing very thin conductors (less than skin depth) by laminated multilayered conductors reduce losses. However, the improvement does not exceed the case of single conductor which is a few times thicker than skin depth. Secondly, the efficiency improvement of a small H-Shaped patch antenna by using closely coupled stacked parasitic resonators is studied. It is shown that significant improvement in efficiency can be achieved with minimal changes in the foot print, radiation pattern and cross polarization levels of the antenna. The effect of the overall thickness and superstrate dielectric constant on the efficiency improvement is studied parametrically. It is shown that by using 5 radiating resonators and appropriate choice of inter-conductor dielectric constant, for a small increase in thickness of 0.127mm (5mil), the radiation efficiency can be increased from 2.34% to 6.3%. This efficiency improvement can be made very significant from 2.4% to 33%, by increasing the height to 1.27mm (50mil). These translate to a gain improvement of 4dB and 13dB, respectively. This technique is also demonstrated experimentally in H-Shaped antennas with two different levels of miniaturizations. / October 2015

ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / This research article reports a design of a wide band multilayer microstrip patch antenna (MSPA). Positions of a coaxial probe feed to main patch of the multilayer MSPA, widths and lengths of main and parasitic patches, and height of a Rohacell foam layer in the multilayer MSPA were optimized to achieve desired performance in L-band. The work also reports a design of a two-by-two array of multilayer MSPA. We present results on antenna radiation patterns and return loss obtained with full wave finite element simulations with Ansoft HFSS software and measurements with a vector network analyzer.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / Patch panels are still frequently used in telemetry installations as a means for routing signals during and in between missions. These patch panels have been used for decades and have many benefits operationally speaking. Digital switching matrices on the other hand, while very popular in the broadcasting and music industries, are not being fully utilized in the telemetry world. Digital switches offer many of the same benefits of patch panels along with an abundance of added features including signal conversion and distribution. This paper describes the benefits of migrating from patch panels to digital switching matrices. It will discuss both the pros and cons of each technology as well as look at the short term and long term cost implications of each. This paper will also discuss return on investment and operational improvements that can be gained from utilizing digital switching matrices in place of patch panels.

No description available.

1 / Yanyan Jiang

A compact multiband antennas for Long Term Evolution (LTE) applications is a challenge. Both the frequencies of new wireless technologies and new frequency bands must be covered. The lower end of the 0.7- 3.5 GHz band is especially difficult to handle for miniaturized terminal devices. A single layer, line-feed rectangular microstrip patch antenna is small enough for the LTE handsets. Our project proposes size reduction and bandwidth enhancement through adapted feeding techniques. By means of slits the return loss and gain can be optimized with the aid of HFSS (High Frequency Structure Simulator).

This work approaches the problem of triangulating algebraic curves/surfaces with a subdivision-style algorithm using A-Patches. An implicit algebraic curve is converted from the monomial basis to the bivariate Bernstein-Bezier basis while implicit algebraic surfaces are converted to the trivariate Bernstein basis. The basis is then used to determine the scalar coefficients of the A-patch, which are used to find whether or not the patch contains a separation layer of coefficients. Those that have such a separation have only a single sheet of the surface passing through the domain while one that has all positive or negative coefficients does not contain a zero-set of the surface. Ambiguous cases are resolved by subdividing the structure into a set of smaller patches and repeating the algorithm. Using A-patches to generate a tessellation of the surface has potential advantages by reducing the amount of subdivision required compared to other subdivision algorithms and guarantees a single-sheeted surface passing through it. This revelation allows the tessellation of surfaces with acute features and perturbed features in greater accuracy.

The transmembrane protein prestin forms an integral part of the mammalian sense of hearing by providing the driving force for the electromotility of the outer hair cell, a specialized cell that resides within the cochlea. This provides the cochlea with an ability to amplify mechanical vibrations, allowing for a high degree of sensitivity and selectivity in auditory transduction. The phenomenon, driven by changes in the transmembrane potential, is thought to be the result of conformational changes in self-associating prestin oligomers. We have previously utilized Forster resonance energy transfer (FRET), by both sensitized emission and acceptor photobleach methods, to detect prestin self -association. While these methods can qualitatively confirm prestin-prestin association, determining nanoscale changes in prestin organization requires greater accuracy than either technique provides. In this thesis, a FRET methodology based on fluorescence lifetime imaging (FLIM), detected by time correlated single photon counting (TCSPC), is implemented and utilized to quantitatively measure conformational changes within prestin-prestin oligomers in response to voltage stimulus.

This work approaches the problem of triangulating algebraic curves/surfaces with a subdivision-style algorithm using A-Patches. An implicit algebraic curve is converted from the monomial basis to the bivariate Bernstein-Bezier basis while implicit algebraic surfaces are converted to the trivariate Bernstein basis. The basis is then used to determine the scalar coefficients of the A-patch, which are used to find whether or not the patch contains a separation layer of coefficients. Those that have such a separation have only a single sheet of the surface passing through the domain while one that has all positive or negative coefficients does not contain a zero-set of the surface. Ambiguous cases are resolved by subdividing the structure into a set of smaller patches and repeating the algorithm. Using A-patches to generate a tessellation of the surface has potential advantages by reducing the amount of subdivision required compared to other subdivision algorithms and guarantees a single-sheeted surface passing through it. This revelation allows the tessellation of surfaces with acute features and perturbed features in greater accuracy.

Diss.--Chimie--Göteborg--Université de Göteborg, 2001. / Bibliogr. p. 63-70. Index.