Design and analysis of an electrically small inductively loaded sector antenna for frequency reconfiguration using varactor diodes

Global wireless communications networks are facing an ever increasing demand to deliver content to the consumer. Along with increased consumption of wireless bandwidth, consumers demand that their devices interface with a plethora of different wireless bands and protocols. To meet this demand, mobile devices have a multiplicity of antennas designed to work for specific bands. However, as mobile communication demands continue to grow, the number of antennas will become even more constrained by size and cost. In order 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 WiMAX bands. The antenna developed is modified from a previous design for frequency reconfiguration using varactor diodes placed in inductive loads. In order to allow for frequency agility, a DC bias network is carefully designed utilizing blocking capacitors to allow for an impedance match over the bands of interest. Characterization of the antenna on different ground plane sizes and construction issues are also addressed. Finally the inductively loaded, electrically small, frequency reconfigurable, sector antenna is fabricated and measured to confirm the simulation analysis. Comments on the radiation patterns, efficiency, and gain are also provided.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Dawson, Steven M.

Contributors dc:contributor

• Bernhard, Jennifer T.

• Electrically small
• antenna
• frequency agile
• varactor tuned antenna

Statement dc:rights

• Copyright 2011 Steven M. Dawson

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/26117

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/26117