An X-band frequency-stabilized MIC Gunn oscillator of a very simple structure using a dielectric resonator is developed. It is studied how the oscillating characteristics can be controlled by circuit parameters, with special attention to the factors affecting the frequency stability with temperature. By optimizing these factors and by selecting the proper temperature coefficient of a newly developed dielectric resonator, the high frequency stability of less than ±100 kHz over the temperature range from -20 to 60 o C (2X10 -7 / o C) was obtained. Copyright © 1979 by The Institute of Electrical and Electronics Engineers, Inc.