An alternative approach for the design of a voltage‐controlled oscillator is proposed. It consists of using an appropriate field effect transistor which exhibits height value of constant transconductance and a high slope of gate capacitance. An MMIC realization using HEMTs is presented with experimental results obtained in X‐band. A minimum output power of 17 mW with a voltage tunable over a 17 percent bandwidth centered at 10.2 GHz is obtained. © 1992 John Wiley & Sons, Inc.