Performance Improvement and Applications of Biomimetic Electrically Small Antenna Arrays

مرکز و کتابخانه مطالعات اسلامی به زبان های اروپایی

منو

" Performance Improvement and Applications of Biomimetic Electrically Small Antenna Arrays "
Ranjbarnikkhah, Mohammad Behdad, Nader

Document Type	:	Latin Dissertation
Language of Document	:	English
Record Number	:	1110455
Doc. No	:	TLpq2486111709
Main Entry	:	Behdad, Nader
	:	Ranjbarnikkhah, Mohammad
Title & Author	:	Performance Improvement and Applications of Biomimetic Electrically Small Antenna Arrays\ Ranjbarnikkhah, MohammadBehdad, Nader
College	:	The University of Wisconsin - Madison
Date	:	2019
student score	:	2019
Degree	:	Ph.D.
Page No	:	130
Abstract	:	Recently a class of biologically-inspired electrically-small antenna arrays have been reported. Referred to as biomimetic antenna arrays (BMAAs), these antennas mimic the hyperacute senses of directional hearing of small animals. First we present a two-element tunable biomimetic antenna array (BMAA) that uses a single varactor to achieve tunability over a relatively wide band. The ECN is designed to allow for tuning the response of the BMAA. Over this frequency range, the proposed BMAA can enhance the phase difference between the output signals compared to a conventional array while extracting the maximum available power from the incoming wave. Then, we present a three-element biomimetic antenna array (BMAA) with an electrically-small triangular lattice. The proposed array consists of three identical quarter-wavelength-long monopoles each positioned at a corner of an equilateral triangle. It will allow for resolving ambiguities problem when such BMAAs are used in small-aperture direction finding systems. The three strongly-coupled antennas are connected to an external coupling network with three inputs and three outputs. This network augments the mutual coupling between the strongly-coupled antennas and is designed to maximize the output phase difference between each two antenna elements without sacrificing the output power level of the array compared to a conventional array occupying the same aperture. Then, we present the performance of multi-input-multi-output (MIMO) communications systems that exploit biomimetic antenna arrays (BMAAs) with electrically-small aperture dimensions. By exploiting the mutual coupling between closely-spaced radiating elements and extracting the maximum available power from all excitation modes of the array, BMAAs can significantly outperform conventional antenna arrays with similar aperture sizes. The capacity of MIMO systems using such BMAAs are compared with those that use conventional antenna arrays with the same element types and spacing. Finally we present a design strategy for platform-based antennas operating on electrically-small platforms such as unmanned ground vehicles (UGVs). Specifically, we report the design of a platform-based antenna operating at the lower end of the VHF band for an electrically small UGV. The antenna is mounted on the bottom of the platform resulting in an extremely low profile design and generating vertically-polarized, monopole-like radiation patterns. The design of this low-profile antenna is extended to a two-element antenna array mounted on the same platform and the performance of this array as part of a two-element direction-finding system was investigated through computer simulations.
Subject	:	Electrical engineering
	:	Electromagnetics