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African Teachers  Association-USA

(A.T.A.)

2510 Hamilton Avenue ,Baltimore , MD 21214 .Tel: 443-744-5328

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Doctoral Defense Announcement !!! --Please Read---

DISSERTATION DEFENSE PUBLIC ANNOUNCEMENT

TITLE:                    ANALYTICAL MODEL OF A HELMET MOUNTED CONFORMAL  PATCH ANTENNA FOR AN ASSORTMENT OF CANONICAL SHAPES

SPEAKER:                Boliong Amang, Doctoral Candidate Morgan state University: Contract/ Department of Electrical and Computer Engineering and Army Research Laboratory
DATE:                        Friday March 9, 2012 from 10:00 AM– 12:00 AM 
LOCATION:             Baltimore Marriott Hunt Valley In (ISC/STEM Conference)

ABSTRACT:  There are essentially two approaches employed to solve for the internal resonances of patch antennas on spherical geometries. One method is analytic while the other relies on computer simulations. The analytic techniques rely on approximations (e.g., the cavity model for a patch antenna) to obtain resonances close to the actual resonances of the antenna. These Eigen-value resonances are good starting points for the more exact computer simulations. As mentioned, the most frequently employed analytic technique used to model resonances of a patch antenna presumes simplifying assumptions such as are found in the cavity model. Due to the spherical curvature of the surface of our structures, this approach gives rise to fractional orders of associated Legendre functions. In this presentation, the internal TM field configurations are determined and the methodology for extracting the resonances is reviewed. Spherical geometries can also exploit Schumann’s analytic method - first used for modeling the natural resonances of the earth’s atmosphere presuming the Ionosphere and earth act as perfect electric conductors. Schumann presumed the distance between the earth and the Ionosphere was negligible compared to the radius of the earth. This method can also be applied to patch antennas on spherical geometries and will be discussed. Once approximate resonances are determined, one can then use commercial codes to fine-tune the resonance of the spherical patch antennas. Having constructed and measured the canonical shapes, we will use the analytical starting points for our HFSS optimizer to simulate the resonances using commercial code (HFSS) and compare to measured data. The frequencies ranges predicted for the spherical patch antennas are indeed captured in the measurement. The study clearly links Schumann analysis of earth-ionosphere’s Electromagnetic fields to the analysis of microstrip spherical antennas. The HFSS simulation is in reasonable agreement with the theoretical predictions and measurements. The study of the spherical cap is used as a template for the other canonic geometries.


Figure 1 – Canonical shapes