A novel pulse-carving technique for an externally-modulated wideband frequency-shift-keying (FSK) format is proposed. Synchronous intensity modulation on the FSK signal suppresses undesired transient components generated during the bit transition time. Numerical analysis for the pulse-carving technique employing a Mach-Zehnder modulator driven by a sinusoidal signal indicates that the suppression of the components is typically more than 20dB.
