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Full-Text Articles in Engineering
Stress-Induced Birefringence And Fabrication Of In-Fiber Polarization Devices By Controlled Femtosecond Laser Irradiations, Lei Yuan, Baokai Cheng, Jie Huang, Jie Liu, Hanzheng Wang, Xinwei Lan, Hai Xiao
Stress-Induced Birefringence And Fabrication Of In-Fiber Polarization Devices By Controlled Femtosecond Laser Irradiations, Lei Yuan, Baokai Cheng, Jie Huang, Jie Liu, Hanzheng Wang, Xinwei Lan, Hai Xiao
Electrical and Computer Engineering Faculty Research & Creative Works
Optical birefringence was created in a single-mode fiber by introducing a series of symmetric cuboid stress rods on both sides of the fiber core along the fiber axis using a femtosecond laser. The stress-induced birefringence was estimated to be 2.4 x 10-4 at the wavelength of 1550 nm. By adding the desired numbers of stressed rods, an in-fiber quarter waveplate was fabricated with a insertion loss of 0.19 dB. The stressinduced birefringence was further explored to fabricate in-fiber polarizers based on the polarization-dependent long-period fiber grating (LPFG) structure. A polarization extinction ratio of more than 20 dB was observed …
Electromagnetic Cell With Three-Dimensional Polarization Dynamic Control, Bo O. Zhu, Weng Cho Chew, Lijun Jiang
Electromagnetic Cell With Three-Dimensional Polarization Dynamic Control, Bo O. Zhu, Weng Cho Chew, Lijun Jiang
Electrical and Computer Engineering Faculty Research & Creative Works
An electromagnetic (EM) cell is demonstrated to create the uniform electric field with 3-D polarization dynamic control for the EM compatibility/ interference (EMC/EMI) testing. We utilize 3-D orthogonal slotline structures to build the walls of the EM cell and produce uniform electric field inside the cell by feeding the slotlines in phase and terminating them with matching loads. The uniform electric field is similar to a standing wave produced by the slotline modes propagating in opposite directions. Microwave switches are integrated into the slotlines so that we can choose the operating slotline dynamically and change its orientation in a 3-D …
Differential Signalling In Pcbs: Modeling And Validation Of Dielectric Losses And Effects Of Discontinuities, R. Araneo, Chen Wang, Xiaoxiong Gu, S. Celozzi, James L. Drewniak
Differential Signalling In Pcbs: Modeling And Validation Of Dielectric Losses And Effects Of Discontinuities, R. Araneo, Chen Wang, Xiaoxiong Gu, S. Celozzi, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
This paper focuses on differential signal transmission above ground planes with gaps, taking into account the dielectric and conductive losses of the substrate. An equivalent lumped-circuit is proposed and its suitability is investigated by comparing the obtained numerical results with the measured data. Furthermore the differential to common mode conversion of the waves, while crossing the gap, is theoretically analyzed and experimentally verified.
Application Of A Hybrid Fem/Mom Method To A Canonical Pcb Problem, Yun Ji, J. Chen, Todd H. Hubing, James L. Drewniak
Application Of A Hybrid Fem/Mom Method To A Canonical Pcb Problem, Yun Ji, J. Chen, Todd H. Hubing, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
A hybrid FEM/MOM method was used to solve a canonical printed circuit board (PCB) problem. The PCB is populated with three traces. One is a signal line and the other two are I/O lines that extend beyond the boundary of the board. The finite element method (FEM) was used to model the fields in the volume around the on-board trace. The method of moments (MOM) was employed to model the equivalent surface currents on the board and the current on the off-board traces. The FEM and MOM equations were coupled by forcing the continuity of tangential fields on the dielectric …
The Synthesis Of Patterns Using A Series-Fed Array Of Annular Sector Radiating Line (Anserlin) Elements: Low-Profile, Circularly Polarized Radiators, James L. Drewniak, P. E. Mayes
The Synthesis Of Patterns Using A Series-Fed Array Of Annular Sector Radiating Line (Anserlin) Elements: Low-Profile, Circularly Polarized Radiators, James L. Drewniak, P. E. Mayes
Electrical and Computer Engineering Faculty Research & Creative Works
A series-fed, circularly polarized array of annular sector radiating-line elements that operates over a ground plane and has a low profile is presented. Pattern shaping can be achieved through control of the fraction of the incident power that is radiated by each element. This can be accomplished over a wide range by a simple adjustment in the geometry of each element. A synthesis technique is given, and experimental results are presented. The array is demonstrated to have a high return loss (good impedance match) and a low axial ratio
Anserlin. A Broad-Band, Low-Profile, Circularly Polarized Antenna, James L. Drewniak, P. E. Mayes
Anserlin. A Broad-Band, Low-Profile, Circularly Polarized Antenna, James L. Drewniak, P. E. Mayes
Electrical and Computer Engineering Faculty Research & Creative Works
A technique is presented for improving the performance of low-profile, circularly polarized (CP) radiating-line antennas. The essential elements of the technique pertain to establishing a single traveling wave on an annular sector of conducting strip that is positioned parallel and close to a large conducting surface. The antenna is named the annular sector, radiating-line (ANSERLIN) antenna. Using this technique, the impedance bandwidth becomes so large that it no longer has any bearing on the operating bandwidth. Instead, the pattern shape and axial ratio become the factors that limit the bandwidth. Both senses of circular polarization can be transmitted or received …
A Log-Spiral, Radiating-Line Antenna, James L. Drewniak, P. E. Mayes, D. Tanner, R. Waller
A Log-Spiral, Radiating-Line Antenna, James L. Drewniak, P. E. Mayes, D. Tanner, R. Waller
Electrical and Computer Engineering Faculty Research & Creative Works
No abstract provided.