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525.418 - Antenna Systems Course Homepage

Instructor Information

Steven Weiss

Work Phone: (301) 394-1987

Course Information

Course Description

This course develops fundamental antenna concepts and uses them to analyze basic antenna systems. Physical as well as electrical characteristics are considered for a variety of applications. Examples of actual systems are presented and recent advances discussed. Topics include physical principles of radiation and dipole and loop polarization. Basic antenna concepts include wire radiators, linear and planar arrays, horns, reflecting and nonreflecting apertures, lenses, broad-band systems, printed circuit antennas, and antenna measurements.

Prerequisites

A course in microwave engineering, such as 525.423 Principles of Microwave Circuits or 525.420 Electromagnetic Transmission Systems.

Course Goal

The goal of the course is to introduce develop fundamental antenna concepts and use them to analyze basic antenna systems. Physical as well as electrical characteristics are considered for a variety of applications.  Examples of actual systems are presented. Topics include wire radiators, linear and planar arrays, loop, horn, and patch antennas.  Antenna measurements are discussed in detail.

Course Objectives

  • Reveiw mathematical techniques needed for the course, and establish a clear understanding of how Maxwell's equations are applied to antenna theory.
  • Present and develop insight into basic antenna concepts: polarization, aperture size, radiation resistance, E-plane, H-plane, co-polarization, cross-polarization, beamwidth, bandwidth, Friis transmission formula, etc.
  • Present and develop insight into basic antenna array concepts: Array factors, tradeoffs using different array distributions, grating lobes, beam squint, scan blindness, etc.

When This Course is Typically Offered

 
Fall and Spring semesters at the Kossiakoff center on Monday evenings.

Syllabus

Topics Covered

  • Introduction to fundamental antenna concepts (beamwidth, bandwidth, etc.), review of phasors, and mathematical techniques, time average Poynting vector.
  • Coordinate systems, transformation of unit vectors, review of Maxwell’s equations, vector potentials, delta functions, Green’s functions.
  • Determination of the free-space Green’s function. Simplification of the curl operation in the far field, analysis of a dipole, definitions of fundamental antenna parameters (gain, directivity, E-plane, H-plane).
  • Polarization of antennas, polarization loss factor, Volume/surface current densities, effect of aperture size on beam, Kraus approximation for directivity.
  • Circuit representation of antennas, reciprocity of transmit and receive patterns.
  • The Friis transmission formula, effective aperture, and driving point impedance of a dipole. Loop antennas. Loop of current and magnetic dipole equivalence, electric and magnetic dipoles over perfect conductors, Helix antenna. Review for the midterm.
  • Midterm exam
  • Array fundamentals. Uniform arrays, beamwidth and sidelobe calculations, generalized array factors.
  • Binomial and other array distributions. Grating lobes and scan blindness.
  • Continued analysis of arrays, discussion of constant phase shift versus true-time delay, beam squint.
  • Antenna measurements: co-polarization, cross-polarization, circular polarization, axial ratio, limitations of anechoic chambers.
  • Noise in antenna systems. Fourier Transforms in antenna theory. Radiation by Horn antennas.
  • Selected topics. Review for final.
  • Final exam

Student Assessment Criteria

Homework 20%
Midterm exam 40%
Final exam 40%

Textbooks

Textbook information for this course is available online through the MBS Direct Virtual Bookstore.

Course Notes

There are no notes for this course.

(Last Modified: 07-22-2008 at 11:07:57 AM)