Generation and detection of millimeter waves by picosecond photoconductivity

Picosecond photoconductors in the form of dielectric resonators have been used to generate and detect extremely short bursts of millimeter wave radiation at 55 GHz with a repetition rate of 100 MHz. Both the generator and detector are tuned to a frequency which is determined by the length of the photoconducting dielectric resonators. The detector, which is phase coherent, has an estimated noise equivalent power of only 4×10−11 W for an integration bandwidth of 1 Hz, and is capable of resolving time intervals corresponding to a small fraction of one millimeter-wave cycle.