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Title: Phase and group delays for circularly-polarized microstrip antennas.

Abstract

No abstract prepared.

Authors:
 [1];  [1]; ;  [2]
  1. (University of Houston, Houston, TX)
  2. (University of Houston, Houston, TX)
Publication Date:
Research Org.:
Sandia National Laboratories
Sponsoring Org.:
USDOE
OSTI Identifier:
902559
Report Number(s):
SAND2006-0386C
TRN: US200718%%10
DOE Contract Number:
AC04-94AL85000
Resource Type:
Conference
Resource Relation:
Conference: Proposed for presentation at the IEEE AP URSI 2006 held July 9-14, 2006 in Albuquerque, NM.
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; ANTENNAS; MINIATURIZATION; PHASE STUDIES; POLARIZATION

Citation Formats

Jackson, David R., Williams, Jeffery T., Basilio, Lorena I., and Dong, Weixin. Phase and group delays for circularly-polarized microstrip antennas.. United States: N. p., 2006. Web.
Jackson, David R., Williams, Jeffery T., Basilio, Lorena I., & Dong, Weixin. Phase and group delays for circularly-polarized microstrip antennas.. United States.
Jackson, David R., Williams, Jeffery T., Basilio, Lorena I., and Dong, Weixin. Sun . "Phase and group delays for circularly-polarized microstrip antennas.". United States. doi:.
@article{osti_902559,
title = {Phase and group delays for circularly-polarized microstrip antennas.},
author = {Jackson, David R. and Williams, Jeffery T. and Basilio, Lorena I. and Dong, Weixin},
abstractNote = {No abstract prepared.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}

Conference:
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  • This paper presents a quasi-analytical technique to design a continuous, all-dielectric phase correcting structures (PCSs) for circularly polarized Fabry-Perot resonator antennas (FPRAs). The PCS has been realized by varying the thickness of a rotationally symmetric dielectric block placed above the antenna. A global analytical expression is derived for the PCS thickness profile, which is required to achieve nearly uniform phase distribution at the output of the PCS, despite the non-uniform phase distribution at its input. An alternative piecewise technique based on spline interpolation is also explored to design a PCS. It is shown from both far- and near-field results thatmore » a PCS tremendously improves the radiation performance of the FPRA. These improvements include an increase in peak directivity from 22 to 120 (from 13.4 dBic to 20.8 dBic) and a decrease of 3 dB beamwidth from 41.5° to 15°. The phase-corrected antenna also has a good directivity bandwidth of 1.3 GHz, which is 11% of the center frequency.« less
  • A thin-crystal Si (400) Bragg transmission x-ray phase plate has been constructed for the production of 5 to 12 keV circularly polarized x-rays. Using multiple beam diffraction from a GaAs crystal, a direct measurement of the degree of circular polarization as a function of off-Bragg position was made. These measurements indicated nearly complete circular polarization ({vert_bar}P{sub c}{vert_bar} {ge} 0.95) and full helicity reversal on opposite sides of the rocking curve.
  • The authors have constructed an x-ray phase plate to produce both linearly and circularly polarized x-rays at discrete energies between 20 keV and 88 keV. The plate is a monolithic two-crystal design, constructed from germanium, which increases the resultant degree of circular polarization of the output beam. They have measured the degree of circular polarization at 65 keV to be 90% {+-} 4%, significantly better than that produced by silicon phase plates. This radiation was used to measure the magnetic Compton profile for Fe, which was found to be in good agreement with theory and previous work. The underlying x-raymore » optics and the characterization of the device between 62 keV and 93 keV at the Cornell High Energy Synchrotron Source are presented.« less
  • A simple and efficient computer-controlled setup for measuring near fields has been realized. It uses the modulated scatterer technique, together with a homodyne receiver to measure both the amplitude and phase of the fields. To move the probe, a standard plotter is used. Special probes have been designed for measuring all field components.
  • A straightforward numerical analysis of large arrays of arbitrary contour (and possibly missing elements) requires large memory storage and long computation times. Several techniques are currently under development to reduce this cost. One such technique is the GIFFT (Green's function interpolation and FFT) method discussed here that belongs to the class of fast solvers for large structures. This method uses a modification of the standard AIM approach [1] that takes into account the reusability properties of matrices that arise from identical array elements. If the array consists of planar conducting bodies, the array elements are meshed using standard subdomain basismore » functions, such as the RWG basis. The Green's function is then projected onto a sparse regular grid of separable interpolating polynomials. This grid can then be used in a 2D or 3D FFT to accelerate the matrix-vector product used in an iterative solver [2]. The method has been proven to greatly reduce solve time by speeding up the matrix-vector product computation. The GIFFT approach also reduces fill time and memory requirements, since only the near element interactions need to be calculated exactly. The present work extends GIFFT to layered material Green's functions and multiregion interactions via slots in ground planes. In addition, a preconditioner is implemented to greatly reduce the number of iterations required for a solution. The general scheme of the GIFFT method is reported in [2]; this contribution is limited to presenting new results for array antennas made of slot-excited patches and cavity-backed patch antennas.« less