A frequency modulated mm-wave interferometer with a single sideband upconverter

A frequency modulated interferometer is developed, which uses a 94 GHz Gunn oscillator and a single sideband (SSB) upconverter as a frequency modulato r. An SSB upconverter makes it possible to use a heterodyne phase measureme nt technique with one mm-wave source. In addition, the influence of frequen cy drift and phase noise of a mm-wave source on the phase measurement can b e reduced. In this work, the performance of a SSB upconverter as a frequenc y modulator is examined. Also, overall performance of the mm-wave interfero meter with a SSB upconverter and line density measurement results in a mirr or device are described. (C) 1999 American Institute of Physics. [S0034-674 8(99)03305-5].