Gigahertz planar photoconducting antenna activated by picosecond optical pulses

We have generated 1-20-GHz microwave pulses by illuminating an Fe-compensated InP wafer with 50-ps optical pulses at normal incidence. The process of the generation of microwave radiation was monitored and analyzed directly through a 40-GHz sampling oscilloscope with precision. The saturation properties, the waveform evolution, and the optical coupling efficiency of the gigahertz photoconducting antenna are discussed. The flexibility, compactness, and high-resolution features offered by this technique merit new applications for radar communication as well as for other microwave detecting devices.