A vacuum plasma generator is used for treating workpieces in a vacuum chamber. The vacuum plasma generator includes a mains connection for connection to a voltage supply network, and at least one mains rectifier. The at least one mains rectifier is connected to at least one first converter that generates at least one intermediate circuit voltage, a first RF signal generator, a second RF signal generator, and at least one 3 dB coupler. The first RF signal generator is connected to at least one intermediate circuit voltage, for generating a first signal of a basic frequency and of a first phase position. The second RF signal generator is connected to at least one intermediate circuit voltage, for generating a second signal of the basic frequency and of a second phase position. The least one 3 dB coupler couples the first and the second signal into an output signal of the generator.