THE GRADUATE COURSE IN ELECTROMAGNETICS: INTEGRATING

THE PAST, PRESENT, AND FUTURE

David A. Rogers & Benjamin D. Braaten

Electrical and Computer Engineering

North Dakota State University

Fargo, ND

First Graduate Course in Electromagnetics

• 30-50 years ago – textbooks by Plonsey and Collin and Collin

• Emphasized: • Maxwell’s Equations

• Analytical Solutions: open- and closed structures

• Followed undergrad cousin with increased rigor

• Theoretical emphasis increased following Sputnik

• Thorough vector calculus descriptions

Typical outline 50 years ago

• Gauss’s flux and divergence theorems

• Poisson’s equation

• Three common coordinate systems

• Curvilinear coordinates

• Green’s identities

• Dirichlet and Neumann conditions

• Uniqueness Theorem

• In essence, quite theoretical/mathematical

Early Textbook Details

• Plonsey, R. and Collin, R. E. (1961). Principles and Applications of Electromagnetic Fields. New York, NY: McGraw-Hill.

• Collin, R. E. (2001). Foundations for Microwave Engineering. New York, NY: IEEE Press.

Grad Course in Electromagnetics 20-30 years ago.

• Textbooks by Pozar, Balanis, Ishimaru

• Advanced electromagnetics • Boundary value problems

• Reflection and transmission

• Microwave device design and analysis

• Microstrip design techniques

• Microwave filters

• Microwave networks

20-30 years ago (continued)

• Waveguides using vector potential methods

• Magneto-ionic media

• Propagation in the neutral atmosphere

• Cavities

• Intermediate mathematics of electromagnetics

Classical Textbook Details

• Balanis, C. A. (2012). Advanced Engineering Electromagnetics. Hoboken, NJ: Wiley.

• Ishimaru, A. (1991). Electromagnetic Wave Propagation, Radiation, and Scattering. Englewood Cliffs, NJ: Prentice Hall.

• Pozar, D. M. (2005). Microwave Engineering. Hoboken, NJ: Wiley.

A Contemporary Course

• Maxwell’s equations review • Plane waves, lossy media, reflection and

transmission • Transmission-line theory, losses, matching stubs • Microstrip design • Microstrip devices: couplers, splitters, matching

devices • Metallic waveguides • General solutions for guided-wave structures • Human effects of electromagnetic waves/ethics

A Contemporary Course (Continued)

• Microwave network theory

• Antennas, gain, noise, and systems studies

• Radio propagation and scattering

• Magneto-ionic theory

• Fiber optics

• Matrix method in networks

• Project presentations

Contemporary Textbook Details

• Pozar, D. M. (2012). Microwave Engineering. Hoboken, NJ: Wiley.

• 2012 edition is scheduled for release in November 2011.

What will our students need?

• Course should serve grad students specializing in electromagnetics.

• Should attract non-specialists.

• Serve those working with high-speed or very small devices—material science, nanoscale science/engineering, certain areas of applied physics, and specialists in optics.

What do the students bring to the course?

• An undergraduate electromagnetics course.

• Phasor analysis of AC circuits.

• Transmission line theory.

• Plane wave background.

• The usual physics and math common to undergrad engineering and physics students.

Computer and laboratory work

• Early in the semester students begin a project,

groups of two or three students. • Design a microwave device. • Layout and simulate on the computer. • Forward to ProtoMat S62 milling machine.

(www.lpkf.com ) • Measure using Agilent E5071C (4.5 GHz) network

analyzer. • Compare to Advanced Design System (ADS) and

Matlab simulations. • Present oral and written reports.

Have we had an impact on the students?

• Gets students involved in:

• Literature searches • Reproducing published results • New designs, new frequencies • ADS layouts and simulations • Testing

• In the course: • Reduce routine homework in favor of the above. • Require student bi-weekly written progress reports and

oral presentations. • Final report to be ready for submission to a conference.

Student Project Procedure: Example: 90o Hybrid Coupler

• Design device based on Pozar or other literature/research.

• Lay out and simulate device using ADS.

• Send gerber file to ProtoMat S62 PCB milling machine.

• Add connectors and loads to the device.

• Determine the performance (scattering parameters) using an Agilent E5071C spectrum analyzer.

ADS Layout for 90o Hybrid Coupler

ProtoMat S62 PCB milling machine

http://sites.google.com/site/ndsuece/Home

Waiting for the Grad Assistant

90o Hybrid Coupler

Network Analyzer

Network Analyzer close-up

Test Results: 90o Hybrid Coupler

-28.92

-3.97

-5.33

-21.43

-40.00

-35.00

-30.00

-25.00

-20.00

-15.00

-10.00

-5.00

0.00

1.5

0

1.5

8

1.6

5

1.7

3

1.8

0

1.8

8

1.9

5

2.0

3

2.1

0

2.1

8

2.2

5

2.3

3

2.4

0

2.4

8

2.5

5

2.6

3

2.7

0

2.7

8

2.8

5

2.9

3

3.0

0

3.0

8

3.1

5

3.2

3

3.3

0

3.3

8

3.4

5

3.5

3

3.6

0

3.6

8

3.7

5

3.8

3

3.9

0

3.9

8

4.0

5

4.1

2

4.2

0

4.2

8

4.3

5

4.4

2

4.5

0

dB

GHz

S Parameters

S11

S12

S13

S14

Design fo = 3Ghz

More Student Project Results

• Power dividers

• “Rat race” coupler

• Quasi-Yagi antenna

• Quasi-Landstorfer antenna

• Bow-tie slot antenna

Student Projects: Power Dividers

1.0 1.2 1.4 1.6 1.8 2.0

-42

-36

-30

-24

-18

-12

S11-Measured

S11-Simulated

Frequency (GHz)

IS11I

(dB

)

-7.0

-6.5

-6.0

-5.5

-5.0

-4.5

-4.0

-3.5

(1.597,-44.206)

(1.549,-28.62)

IS1

2I, IS

21

I) (dB

)

Power divider with resistor

1.0 1.2 1.4 1.6 1.8 2.0

-35

-30

-25

-20

-15

(1.53, -29.33)

(1.486,-36.986) S11-simulation

S11-measured

Frequency (GHz)

IS11I

(dB

)

-7.0

-6.5

-6.0

-5.5

-5.0

-4.5

-4.0

-3.5

-3.0 Power divider without resistor

IS21I, IS

12I (d

B)

Student Project: “Rat Race” Coupler

Student Project: Metamaterial-based Quasi-Yagi Antenna

Student Project: A Quasi-Landstorfer Antenna

Student Project: Bow-tie Slot Antenna

Published/Accepted Results J. Anderson, K. Johnson, C. Satterlee, A. Lynch and B. D. Braaten,

"A Reduced Frequency Printed Quasi-Yagi Antenna Symmetrically

Loaded with Meander Open Complementary Split Ring Resonator

(MOCSRR) Elements," Proceedings of the 2011 IEEE International

Symposium on Antennas and Propagation, Spokane, WA, July 2011.

L. A. Berge, M. Reich and B. D. Braaten, “A Compact Dual-Band

Pseudo-Vivaldi Bowtie Slot Antenna for 900 and 2400 MHz ISM

Bands,” Submitted for review in the IEEE Antennas and Wireless

Propagation Letters – Accepted and under revision.

M. A. Aziz, S. Roy and B. D. Braaten, "A New Printed Quasi-

Lanstorfer Antenna," Accepted for publication in the IEEE

Transactions on Antennas and Propagation.

What are our plans for the department?

• Recruit talented students to participate and be student leaders.

• Integrate active research projects into teaching (Dr. Braaten).

• Active interests: flexible antennas, printed antennas, microwave devices.

• Leverage course activities to increase research in department.

Conclusions

• The course has been an excellent research initiation experience for our students.

• It has drawn students and faculty together in ways that a straight lecture course couldn’t.

• It has been the first step towards several M.S. degrees and a few Ph.D. degrees.

Acknowledgement

• Dr. Robert M. Nelson of UW-Stout made major contributions to the Emag program at NDSU, 1989-2008. He continues to be an inspiration for our work.

Questions?

Thank you for listening!