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Toward Self-biased Ferrite Microwave...

Northeastern University.

Toward Self-biased Ferrite Microwave Devices.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Toward Self-biased Ferrite Microwave Devices.
Author:	Wang, Jianwei.
Description:	140 p.
Notes:	Source: Dissertation Abstracts International, Volume: 72-08, Section: B, page: .
Notes:	Adviser: Carmine Vittoria.
Contained By:	Dissertation Abstracts International72-08B.
Subject:	Engineering, Electronics and Electrical.
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3454880
ISBN:	9781124649252

Toward Self-biased Ferrite Microwave Devices.
Wang, Jianwei.

Toward Self-biased Ferrite Microwave Devices. - 140 p.

Source: Dissertation Abstracts International, Volume: 72-08, Section: B, page: .

Thesis (Ph.D.)--Northeastern University, 2011.

Circulators are important components in modern radar systems. Its non-reciprocal chracteristics make it possible for the radar systems to receive and transmit the signals at the same time and same frequency. However, bulky permanent magnets are required to provide a large static magnetic field in order for the traditional circulator to function properly. This thesis focuses on how to remove the permanent magnets so that size, weight and cost of systems can be reduced.

ISBN: 9781124649252Subjects--Topical Terms:

226981
Engineering, Electronics and Electrical.

Toward Self-biased Ferrite Microwave Devices.
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245 1 0 $a Toward Self-biased Ferrite Microwave Devices.
300 $a 140 p.
500 $a Source: Dissertation Abstracts International, Volume: 72-08, Section: B, page: .
500 $a Adviser: Carmine Vittoria.
502 $a Thesis (Ph.D.)--Northeastern University, 2011.
520 $a Circulators are important components in modern radar systems. Its non-reciprocal chracteristics make it possible for the radar systems to receive and transmit the signals at the same time and same frequency. However, bulky permanent magnets are required to provide a large static magnetic field in order for the traditional circulator to function properly. This thesis focuses on how to remove the permanent magnets so that size, weight and cost of systems can be reduced.
520 $a In-plane circulator requires low-biasing field due to the shape anisotropy of the magnetic substrate. This thesis presents a spectral domain method to assist the analysis of magnetic microstrip line and magnetic coupled microstrip lines. The latter is the main component of the in-plane circulator. The ferrite modeled by this method could be cubic , M-type , Y-type and Z-type ferrites. An in-plane circulator based on YIG(yttrium iron garnet) operating at C band is designed with this method and simulated with AnsoftRTM HFSS. The reflection and isolation is less than 15 dB from 6.3 GHz to 7.8 GHz with a 200 Oe biasing field.
520 $a A self biased junction circulator based on oriented M-type hexaferrite was designed, fabricated and tested. A new topology structure was used to ease the fabrication process and integration with other components. An isolation of 21 dB with corresponding insertion loss of 1.52 dB was measured, which render itself to the first hexaferrite-based self-biased circulator operating below 20 GHz.
520 $a Theoretical models were developed to design self-biased Y-junction circulators operating at UHF frequencies. The proposed circulator design consisted of insulating nanowires of YIG embedded in high permittivity BSTO(barium-strontium titanate) substrates. The model represents the nanowires and the BSTO substrate by an equivalent medium with effective properties inclusive of the average saturation magnetization, dynamic demagnetizing fields, and permittivity. The effective medium approach was validated against the exact calculations and good agreement was observed between the two simulations in terms of calculated S-parameters. Using the proposed approach, a self-biased junction circulator consisting of YIG nanowires embedded in a BSTO substrate was designed and simulated. The center frequency insertion loss was calculated to be as low as 0.16 dB with isolation of -42.3 dB at 1 GHz.
590 $a School code: 0160.
650 4 $a Engineering, Electronics and Electrical. $3 226981
690 $a 0544
710 2 $a Northeastern University. $b Electrical and Computer Engineering. $3 531081
773 0 $t Dissertation Abstracts International $g 72-08B.
790 1 0 $a Vittoria, Carmine, $e advisor
790 1 0 $a Harris, Vincent G. $e committee member
790 1 0 $a Geiler, Anton L. $e committee member
790 $a 0160
791 $a Ph.D.
792 $a 2011
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3454880