A matchless plasma source : for providing radio frequency (RF) power to an electrode of a plasma chamber used for processing a substrate, comprising: a controller , a signal generator configured to provide an input RF signal at an operating frequency in response to a setting by the controller; a gate driver configured to receive the input RF signal and produce a plurality of square wave signals; an amplification circuit configured to receive the plurality of square wave signals from the gate driver and generate an amplified square waveform, the amplification circuit having an agile direct current (DC) rail , wherein the controller is coupled to an arbitrary waveform generator, wherein the controller is configured to send a signal to the arbitrary waveform generator, wherein the arbitrary waveform generator is coupled to the agile DC rail , wherein upon receiving the signal from the controller , the arbitrary waveform generator is configured to generate a shaping voltage signal to set voltage values for the agile DC rail , wherein the voltage values for the agile DC rail are set to shape an envelope of the amplified square waveform to be output from the amplification circuit, wherein the envelope of the amplified square waveform is shaped according to the shaping voltage signal to output a shaped envelope; and a reactive circuit configured to extract a shaped sinusoidal waveform from the amplified square waveform, the shaped sinusoidal waveform being output based on the shaped envelope defined by the shaping voltage signal wherein the reactive circuit is configured to provide the RF power of the shaped sinusoidal waveform to the electrode for generating a plasma for said processing of the substrate. a controller , a signal generator configured to provide an input RF signal at an operating frequency in response to a setting by the controller; a gate driver configured to receive the input RF signal and produce a plurality of square wave signals; an amplification circuit configured to receive the plurality of square wave signals from the gate driver and generate an amplified square waveform, the amplification circuit having an agile direct current (DC) rail , wherein the controller is coupled to an arbitrary waveform generator, wherein the controller is configured to send a signal to the arbitrary waveform generator, wherein the arbitrary waveform generator is coupled to the agile DC rail , wherein upon receiving the signal from the controller , the arbitrary waveform generator is configured to generate a shaping voltage signal to set voltage values for the agile DC rail , wherein the voltage values for the agile DC rail are set to shape an envelope of the amplified square waveform to be output from the amplification circuit, wherein the envelope of the amplified square waveform is shaped according to the shaping voltage signal to output a shaped envelope; and a reactive circuit configured to extract a shaped sinusoidal waveform from the amplified square waveform, the shaped sinusoidal waveform being output based on the shaped envelope defined by the shaping voltage signal wherein the reactive circuit is configured to provide the RF power of the shaped sinusoidal waveform to the electrode for generating a plasma for said processing of the substrate. <EOS>