Microwave frequency synthesizers

The frequency synthesizers operating in the 18-143 GHz range for high precision measurements have been designed. The experience of their design is of interest. In this report a brief description of two synthesizers of millimeter wave-range is presented. Recommendations on frequency synthesizer design are available. The frequency synthesizer of frequency range 18-37 GHz is based on several phase locked oscillators. The phase locked Gunn diode oscillator is applied as output source of radiation.