A multi-port circuit and corresponding method for simultaneous shaping of sub-nanosecond pulses (MCS3P). The MCS3P includes a coupled-line coupler, a Schottky detector diode, and circuitry for compressing the rising and falling edges of a waveform. The MCS3P simultaneously produces square wave, Gaussian, and monocycle waveforms by differentiating a sinusoidal source. The method includes the steps of compressing the rising edge of a sinusoidal source waveform, differentiating the resulting waveform to form a square waveform and a Gaussian waveform, filtering out the positive going Gaussian to produce a negative going Gaussian, differentiating the Gaussian waveform to form a monocycle waveform, and compressing the falling edge of the square waveform to produce a square wave form with both edges compressed.