The mutual coupling in phased array is a well-known phenomenon. It affects the active element pattern of the array as the phase of the individual element is altered. In an array that has many elements, the effect is identical for all the elements that are nearer to the center of the antenna, thus allowing a more predictable scan performance with respect to the phase of the elements. However, in a small array that has only three elements, the active element pattern for the elements at the end can be significantly different from the center element and this affects the predictability of operations such as direction finding. The thesis investigates two ways that can potentially reduce or at least control the mutual coupling in small arrays. The first method simply adds a dummy element with a special load condition to each end of the array to make the edge element "feel" as if there are more elements next to it. The second method uses a passive feedback circuit to both monitor and correct the magnitude and phase of the mutual coupling at the input of each array element. A hybrid ring is attached to each of the elements to monitor the amount of interference received by that element. Simulation results for the dummy element method shows that some reduction in phase error can be achieved if the spacing and length of the element are selected properly. The compensation network approach relies on an efficient two-port array element. The research has focused on the design of a two-port printed circuit dipole that could be used in such an array. The dipole was designed, simulated, and fabricated. Future research will use this element in a compensation network. / Republic of Singapore Navy author.

Thesis (M.S.)--Ohio State University, 2006. / Includes bibliographical references (leaves 98-90). Available online via OhioLINK's ETD Center

Phased array surface coils offer high SNR over a large field of view. Phased array volume coils have high SNR at the surface and centre of the volume. Most array coil designs typically employ a combination of geometrical and additional techniques, such as isolating preamplifiers for element-to-element decoupling. The development of array coils for small animal MRI is of increasing interest. However isolation preamplifiers are expensive and not ubiquitous at the field strengths typically employed for small animal work (4.7T, 9.4T, etc). In addition, isolating preamps complicates the designs of coils for transmit SENSE since they do not decouple during transmitting. Therefore, this thesis reexamines a "tried and true" method for decoupling coil elements. In this work five different coils for mouse imaging at 200MHz are presented: a 16 leg trombone design quadrature birdcage coil and four geometrically decoupled volume phased array coils. The first mouse array coil is a two saddle quadrature coil with a circularly polarized field. The second coil is a four channel transmit/receive volume array coil that is decoupled purely geometrically, without the need for other forms of decoupling. The third array coil is a modified 'open' configuration to facilitate the loading of animals. The fourth coil presented is a 'tunable' decoupling coil, where the geometric decoupling between elements is 'tunable', in order to compensate for different loading conditions of the coil. Tunable decoupling between elements was achieved using two mechanisms, a decoupling paddle for isolation of top to bottom elements, with a variable overlap mechanism for decoupling diagonal elements. Bench measurements demonstrate good decoupling (better than -20dB) of the coil elements and 'tunability' of both mechanisms. Phantom images from all coils are presented.

Thesis (M.S.)--Naval Postgraduate School, 2002. / Thesis advisor(s): Michael Melich, David Jenn, Rodney Johnson. Includes bibliographical references (p. 71-72). Also available online.

Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, September 2003. / Thesis advisor(s): David C. Jenn, Richard W. Adler. Includes bibliographical references (p. 71-72). Also available online.

Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, March 2003. / Thesis advisor(s): David Jenn, Richard Adler. Includes bibliographical references (p. 123). Also available online.

Thesis (ME)--University of South Australia, 1995

Thesis (Ph. D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1993? / Includes bibliographical references (leaves 219-227).

Thesis (MScIng)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Thesis (M.S.) -- Worcester Polytechnic Institute. / Keywords: antenna; dipole; phased array; active loading. Includes bibliographical references (p. 100-102).