The possibility of generating and radiating microwave signals with a duration of only one period of a microwave oscillation is demonstrated. Because of the optoelectronic process this can be effected on a precise time scale within the picosecond range. An integrated device consisting of an antenna and an optoelectronic switch is proposed. Even though the results presented are only preliminary, it is expected that this concept can easily be extended to shorter times and higher powers. By using a well designed antenna, the generation and radiation of picosecond pulses of high power should be possible. The exponentially tapered slot-line antenna is regarded as the most suitable structure at the present time because it can easily be fabricated on the high-permittivity semiconductor substrate using conventional photolithographic techniques. The optoelectronic switch thereby becomes an integral part of this antenna.