Microwave reflection measurements on doped semiconductors with picosecond transient radiation

Broadband microwave reflection spectroscopy using the COMITS (coherent microwave transient spectroscopy) method is described. COMITS is particularly suited to reflection studies because the picosecond transient radiation emitted from planar antennas is strongly linearly polarized. The validity of the technique is verified by reflection measurements on isotropic and anisotropic dielectrics. Reflection studies on a series of doped silicon samples demonstrate that the carrier dynamics in the 15-140-GHz frequency range are well described by a simple Drude model.<>