Final Paper pdf 561KB

Homemade-Antenna Project For An Undergraduate Wave-Propagation Course

Senior electives in an undergraduate engineering program add hands-on practice to theory presented in earlier courses. One such elective, for electrical-engineering majors, is Antennas & Propagation, a course which follows the heavily theoretical Electromagnetic Fields. A core objective is to study the propagation of electromagnetic waves via waveguides and antennas. Unfortunately, access to physical waveguides and antennas is limited. Compared to the equipment required to prototype digital-logic or baseband-analog designs, equipment required to prototype radio-frequency (RF) circuits is orders-of-magnitude more expensive. Thus, such hardware is typically not found in an undergraduate laboratory. Studies of high-frequency circuits and electromagnetic (EM) waves are generally confined to analyzing simple canonical structures using highly-idealized theory. RF design (largely by simulation) becomes accessible at the early-graduate level, while fabrication of EM structures is generally reserved for advanced graduate studies. Presented in this paper is a hands-on project which introduces undergraduates to RF fabrication and testing. The project requires construction of two antennas and demonstration of their functionality. Each antenna is assembled using materials not originally intended to carry electricity (e.g. a paperclip) and interfaced with a coaxial cable feed-line. The signal transmitted by the first antenna originates at a function generator, and the signal received by the second antenna is captured by a digitizing oscilloscope. Both instruments are typically available at an educational laboratory, and such instruments are usually capable of generating and capturing MHz-range radio frequencies. Students submit a report containing a picture of their antennas, data plots demonstrating successful transmission of at least one radio frequency, and a discussion of how each antenna could be modified to achieve a greater signal-to-noise ratio. This paper presents samples of student work and guidance for a professor to expose his/her students to RF prototyping in an undergraduate course.