An embodiment of a plasma ignition system for an internal combustion engine having up to N cylinders includes a power splitter, N phase shifters, N amplifiers, a power combiner network, and up to N radiation devices. The power splitter divides an input RF signal into N divided RF signals. Each phase shifter applies one of multiple pre-determined phase shifts to one of the N divided RF signals to produce N phase shifted RF signals. The N amplifiers amplify the N phase shifted RF signals to produce N amplified, phase shifted RF signals. The power combiner network combines the N amplified, phase shifted RF signals to produce N output RF signals. Each of the radiation devices receives one of the N output RF signals, and produces a plasma discharge when a power level of the output RF signal is sufficiently high.