Design and Development of 1:4 BALUN for HF band

This paper presents the development of a 1 to 4 BALUN utilizing a ferrite core to convert a 50 ohm impedance at the coaxial cable end to a 200 ohm impedance at the considered antenna (LPDA) end, enabling enhanced efficiency in the lower HF band spanning from 3MHz to 15MHz. The primary focus lies in the design and construction of the BALUN to achieve superior common mode rejection (<-30dB) and minimal insertion loss (<0.3dB), while ensuring effective impedance transformation. Detailed discussions encompass core selection, construction methodologies, and measurement setups. Through meticulous design considerations and construction techniques, this research aims to contribute to the advancement of BALUN technology for optimized performance in HF frequency applications.