Design of a VHF guard three-way lumped component unequal high power splitter

Abstract

Implementing microstrip or stripline-based power splitters or couplers for high-power VHF applications is typically prohibitive due to the large wavelength, cost considerations, and power handling. This paper revisits and derives the complete set of design equations for a two-way lumped component Wilkinson’s unequal power splitter by using standard circuit theory, rather than odd and even mode analysis, given the non-symmetric nature of the circuit. Using these equations, a simplified and modular design of a three-way unequal high power splitter for the International Aeronautical Emergency Frequency is presented, while considering a lumped component equivalent circuit of a quarter wavelength transmission line section. A measured return loss of less than dB was obtained on each port at a frequency of 121.5 MHz together with an isolation of around dB from the main output port to the other output ports.