Design of broadband power divider using lumped-elements

Microwave power dividers play important roles in microwave circuit systems. As an in-phase divider, the Wilkinson power divider which consists of two quarter-wavelength transmission lines and a resistor connected between two output ports is well known. However, the circuit size becomes large because this divider is designed based on a distributed circuit theory. This problem is extremely serious at low frequency regions such as VHF and UHF bands. Although some power dividers utilizing ?- or T-networks have been already reported in order to overcome this problem, these dividers have relatively narrow bandwidths. On the other hand, authors have been also proposed broadband lumped-element power dividers utilizing LC-ladder circuits. This paper describes a design method of multi-section LC-ladder dividers at VHF band. The multi-section LC-ladder divider is a broadband lumped-element power divider composed of multi-section LC-ladder circuits and an isolation resistor. By designing the divider based on multi-section impedance transformer and L-type matching techniques, broadband characteristics of a relative bandwidth of over 100% can be obtained at VHF band. Electromagnetic simulation and experiment for the designed divider have been performed in order to verify the design procedure. The measured results of the fabricated LC-ladder divider at a center frequency of 178MHz utilizing commercial chip elements are good agreement with simulation results. © 2020 Institute of Electrical Engineers of Japan. All rights reserved.