Sunday Short Course

Dr. Doren Hess and Dr. Don Bodnar to Present 2009 AMTA

Symposium Short Course

Short Course Outline

Techniques for Improved Accuracy in The Measurement of Gain and Spherical NF Patterns

Introduction to Near-Field & Far-Field Gain Measurement Techniques
Radiation Intensity, Impedance Mismatch, Friis Transmission Formula, Partial Gain, Three-Antenna Method, Gain Extrapolation Technique

Numerical Modeling of Antennas as Standards for Gain Comparison
Approaches to Modeling -- (PO, FDTD, FEM, MoM), Selection of Packages -- (NEC, WIPL, FEKO), Modeling of Pyramidal Horns, Modeling of Port, Requirements for Iteration, Gain versus Frequency, Throat-Aperture Interactions, Comparison to Measurement,

Numerical Modeling of Probe Antennas for Gain by Comparison and Range Insertion Loss
Choice of Probe Antenna Type, Estimate by Analytical Formulas, Yaghjian Model for Open-Ended Rectangular Guide, Approaches to Modeling, Electromagnetic Results, Results as Inputs to NF Algorithms, Examples of NF Gain Measurements

Spherical Near-Field Measurements and the Near-Field-to-Far-Field Algorithm
Maxwell Equations and Spherical Modes, Cutoff of Spherical Modal Sum, Scattering Matrix Description of Antennas, Spherical NF Transmission Equation, Inversion of Transmission Equation, Sampling Criterion for NF Data, Example of Measurement Results

Correction Methods Associated with Spherical Near-Field Scanning
Probe Pattern Correction, Impedance Mismatch Correction, Standing Wave Correction, Thermal Drift Correction, Channel-Balance Correction, Cable Motion Correction, Probe Position Error Correction - Active & Post Processing, Corrections for Extraneous Reflections

Applications of Filtering in the Spherical Modal Domain Back-Projection
Filtering to Remove Nearby Reflections, Filtering to Remove Chamber Reflections, Modeling of Spherical Modal Filtering for Nearby Signals, Back-projection from Far-Field Patterns, Examples of Back-projection from Spherical Near-Field Arch Data

Dr. Doren Hess and Dr. Don Bodnar of MI Technologies

biographies:

Dr. Hess is Senior Staff Engineer at MI Technologies where he focuses on near-field scanning and compact range applications. His work at Scientific-Atlanta, a predecessor company to MI Technologies, centered on industrial applications of compact ranges and near-field scanning. He was responsible for final development of the first compact range and the first commercial spherical near-field test and measurement system. Dr. Hess is a member of the IEEE Antennas and Propagation Society and a past president of the Antenna Measurement Techniques Association which honored him with its Distinguished Achievement Award in 1997.

Dr. Bodnar is Vice President of MI Technologies responsible for the development of new business area and products. He is an internationally known expert in the field of antenna design and analysis, especially scanning reflector antennas and in the polarization characterization of antennas using both theoretical and experimental methods. He has performed antenna and RCS measurements using compact range, near-field and far-field measurement techniques. Dr. Bodnar is a Fellow of the IEEE, past president and vice president of the IEEE Antennas and Propagation Society, and past chairman of the IEEE Antenna Standards Committee.