BS in Electrical Engineering
Electrical Engineering Department
This project explores different balun devices in order to develop a balanced to unbalanced transformer that will operate over a wide bandwidth. The balun must operate from at least 1 MHz (or below) to the highest possible frequency. It must have an insertion loss of less than 1 dB under the ideal case with an imbalance of less than 1 dB and 2.5 degrees. Three balun topologies were tested, each built for a 1:1 impedance transformation ratio. Techniques of measuring each balun topology were investigated including gathering accurate data from a three port device with two port instruments and measuring permeability of magnetic materials. The balun that showed the best results was the Guanella balun wound around 1mm diameter cores from old magnetic core memory matrices. The Guanella balun showed more stable phase difference and insertion loss compared to the other two baluns tested.