Hope College Physics Department
Research Experiences for Undergraduates
Summer 2008
Project Summary


Project Title: Periodic Transmission Lines
Student Name: Isaac Angert
Student's Home Institution: Truman State University
Research Advisor: Dr. Stephen Remillard
Source of Support: This material is based upon work supported by the National Science Foundation under NSF-REU Grant No. PHY-0452206.

 We investigated the physical properties and fabrication challenges of periodic microstrip lines on uniform dielectric substrates at microwave frequencies. Fabrication methods utilized photolithography with Duroid board as well as copper tape on alumina substrates. We discovered that the glue layer in copper tape overlaid on an alumina substrate acts to significantly lower εeff. We also found that much out-of-band loss is due to Fabry-Perot resonances between the ends of the microstrip, which can be minimized through impedance matching. S-parameters were used to calculate microstrip impedance and propagation constant γ, which was used obtain a dispersion graph. These results are compared to full wave EM simulation as well as analytic approximations of periodic structures. While in-band impedance approaches zero for infinite approximations of periodic microstrips, we find nonzero trends in both measured and simulated in-band impedance.

Publications and Presentations:
"Experimental Observation and Control of Wave Dispersion", K.R. McLellan, C.I. Angert, and S.K. Remillard, AAPT Advanced Labs Topical Conference, Ann Arbor, MI, July 23-25, 2009.
"Dispersion in One-Dimensional Photonic Band Gap Periodic Transmission Lines," C. Isaac Angert and S.K. Remillard, Microwave and Optical Technology Letters, 51, no. 4, 1010-1013 (2009).