A novel technique for the generation of 280 picosecond risetime pulsed microwave waveform has been developed. It is based on the mixture of two arbitrary signals, an ultra-fast pulse train and a microwave CW signal, generated from different sources, combined in the optical domain and photodetected, with the maximum preservation of the spectral and temporal features. The technique's concepts and the setup used for the experimental validation are presented. The obtained results are discussed and compared to the pulsed microwave signals generated by a modern commercial microwave generator. © 2007 IEEE. 180183Ross, G.F., Transmission and reception system for generating and receiving base-band pulse communication system, (1973), U.S. Patent 3 728 632, Apr. 17Fontana, R.J., Larrick, J.F., Waveform adaptive ultra-wideband transmitter, (2000), U.S. Patent 6 026 125, Feb. 15Ked, U.D., Dykaar, D.R., Ultrafast Pulse Generation in Photoconductive Switches (1996) IEEE Journal of Quantum Electronics, 32 (9), pp. 1664-1671. , SepHolzman, J.F., Vermeulen, F.E., Elezzabi, A.Y., Ultrafst Photoconductive Self-Switching of Subpicosecond Electrical Pulses (2000) IEEE Journal of Quantum Electronics, 36 (2), pp. 130-136. , FebMourou, G., Methods and Apparatus for Generating Microwave Pulses and for the Measurement and Control Thereof (1980), U.S. Patent 4 329 686, Jun. 18Jalali, B., Chou, J., Han, Y., Ultra Wideband Microwave-Photonic Arbitrary Waveform Generator (2003) IMTC 2003 - Instrumentation and Measurement Technology Conference, , Vail. CO, USA, MayGallep, C.M., Conforti, E., Simulations on picosecond nonlinear electro-optic switching using an ASE-calibrated semiconductor optical amplifier model (2004) Optics Communication, 236 (1-3), pp. 131-139