A highly linearised mm-wave voltage controlled oscillator for FMCW radar applications

The author describes a technique of frequency feedback by which the linearity of a voltage controlled Gunn effect oscillator may be improved from a natural value of around 10% to a linearised value of less than 1%. He includes a description of how the lineariser is constructed using quartz microstrips for the mm-wave elements and thick film hybrid techniques for low frequency components. Results of linearity measurements are represented.