Course description (2005-2007 University Catalog):
E
E 417. Electromagnetic Radiation, Antennas, and Propagation. (Dual-listed
with 517.) (3-3) Cr. 4. S. Prereq: 311. Fundamental antenna concepts.
Radiation from wire-and aperture-type sources. Radio transmission formulas. Wave
and antenna polarization. Antenna arrays. Modern antenna topics. Practical
antenna design. Antenna noise. Radiowave propagation in the presence of the
earth and its atmosphere. Antenna measurements and computer aided analysis.
Nonmajor graduate credit.
Prerequisite:
EE 311, Electromagnetic Fields and Waves.
Textbook: C. A. Balanis, Antenna Theory: Analysis and Design, 3rd Ed., John Wiley & Sons, 2005.
Course Coordinator: Jiming Song.
Objectives: On completion of EE 417/517 the student will be able to do the following:
1. Define the following terms: isotropic antenna, radiation intensity, gain, directivity, radiation efficiency, phase center, effective area, effective length, polarization, radiation resistance, bandwidth, radiation pattern, beamwidth, sidelobe level, grating lobes, aperture efficiency, aperture taper efficiency, spillover, and (for a reflector antenna) primary and secondary patterns.
2. Given the gain of an antenna and the power it accepts from a source, calculate (in the far field in free space) the radiated power density and the electric and magnetic field intensities at a given distance. Compare to the levels specified in IEEE Standard C95.1-1991, and assess potential hazards from radiation exposure.
3. Derive the Friis transmission formula. Define radar cross section, and derive the radar formula.
4. Calculate the response of a receiving antenna to an incoming wave when the antenna and wave polarizations may be different.
5. Define "far field," and determine the minimum distance at which far-field conditions may be assumed to exist for a given antenna. State some requirements for a good anechoic chamber for antenna testing.
6. Given a uniform linear array of antennas, calculate the progressive phase shift of excitation to produce a main beam in a desired direction. Alternatively, given the progressive phase, calculate the directions of the main beam, and of grating lobes if there are any.
7. State the principle of pattern multiplication. Use it to find the radiation pattern of an array of identical elements. By successively applying this principle, determine the excitation amplitudes for a broadside array with no sidelobes (i.e., the binomial array).
8. Describe qualitatively the way in which equivalent sources are used to determine the radiating characteristics of aperture-type antennas. Describe in general the effects of excitation amplitude taper on directivity, beamwidth, and sidelobe level.
9. Given a receiving system of cascaded components with individual gains and noise temperatures or noise figures, operating at a given frequency and bandwidth with a given receiving antenna, estimate the overall noise temperature and noise power referred to the system input.
10. Define "Fresnel zone clearance" in terms of interference between direct and ground-reflected waves, and determine whether it exists given a propagation path profile. Explain why a 4/3-earth-radius is used for profiling.
11. Describe qualitatively the effect of the earth's ionosphere on radiowave propagation at different frequencies.
12. Explain qualitatively the operation of a wire antenna, a Yagi-Uda array, a microstrip antenna, and a log-periodic dipole array, and discuss their advantages and disadvantages.
13. Use basic laboratory equipment to measure gains and radiation patterns of antennas.
14. Use a moment-method numerical analysis program to model and analyze the fields from an antenna system.
Class schedule and topics covered:
2 weeks Basic radiation concepts, definitions of terms
1 week Dipoles and linear antennas
1 week Friis and radar formulas, polarization mismatch
1 week Numerical analysis: method of moments
2 weeks Antenna arrays
1 week Loop antennas, folded dipoles, feeding & baluns
1 week Yagi-Uda arrays, microstrip antennas, helical antennas
1 week Broadband and frequency-independent antennas
2 weeks Radiation from apertures; slot, horn, and parabolic reflector antennas
1 week Antenna and receiving system noise properties
2 weeks Radiowave propagation in presence of earth and its atmosphere
Laboratory tasks:
1. Introduction to antenna measurements; safety aspects of RF exposure
2. Inverse-distance-squared behavior and location of phase center
3. Measurement of antenna gain
4. Radiation pattern measurement
5. Demonstration of pattern multiplication
6. Numerical modeling of wire antennas, arrays, and scatterers
Contribution of course to meeting the professional component; relationship of course to program objectives:
Engineering Topics, 4 credits. This course contributes to students' development in ECPE Department outcomes A-1, B-1, B-3, B-4, C-1, and C-3 (or EC2000 outcomes a, b, c, e, g, i, and k).
Prepared by: David T. Stephenson, May 19, 2000;
rev. January 8, 2001, by David T. Stephenson.
rev. January 19, 2003, by Jiming Song.
rev. January 11, 2004, by Jiming Song.
rev. February 15, 2006, by Jiming Song.