2026-09-20T13:47:09Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/73100 2023-07-11 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Bernhard, Jennifer T. Outwater, John 2015-01-21T19:59:30Z 2015-01-21T19:59:30Z 2017-01-22T10:15:32Z 2014-12 2015-01-21 2014-12 ESPAR antennas can direct radiation and steer nulls by using variable passive elements like varactors, avoiding the cost and complexity of devices like phase shifters. Past attempts to design multi-band ESPARs have often superimposed multiple antenna arrays, each scaled for a different frequency band. This often results in large, cluttered, complicated designs. To accommodate multi-band operation the radiators can be loaded with reactive elements. To preserve the array properties across bands, a means to control the coupling between driven and parasitic elements is needed. The control mechanisms must be inexpensive and simple to implement. They should not fundamentally alter the array design procedure, but rather compliment it. This study investigates the effects of different approaches to controlling coupling through reactive loading, develops a design procedure and implements it to synthesize an ESPAR that operates at 2.4 GHz and 3.5 GHz. These experiments help further develop a principled method of designing frequency-reconfigurable ESPARs. Since stationary base station antennas can afford to be larger and more complex, these low-profile and inexpensive antennas can find use in femtocells for mobile ad-hoc networks and other portable devices. Item withdrawn by Laura Spradlin (lspradl2@illinois.edu) on 2014-12-10T18:49:32Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Outwater_John.pdf: 16340001 bytes, checksum: edac3030fef3b0fa67ca5380a4dd3b59 (MD5) Made available in DSpace on 2015-01-21T19:59:30Z (GMT). No. of bitstreams: 1 John_Outwater.pdf: 16340001 bytes, checksum: edac3030fef3b0fa67ca5380a4dd3b59 (MD5) Embargo set by: Seth Robbins for item 73289 Lift date: 2017-01-21T19:59:39Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Limited Restriction Lifted for Item 73289 on 2017-01-22T10:15:32Z. http://hdl.handle.net/2142/73100 en Copyright 2014 John M. Outwater Jr. array parasitic array espar Controlling coupling in an electrically steerable parasitic array text Electrical & Computer Eng 1933 Electrical & Computer Engr 1200 University of Illinois at Urbana-Champaign Thesis M.S. MS:Electr & Computer Eng-UIUC 10KS1200MS