An efficient design method of microwave oscillator circuits for minimum phase noise

In this paper, we describe a newly developed design method of high-Q microw ave oscillator circuits leading to the minimum phase noise for a given tran sistor and resonator. The key point of the method is the maximization of th e energy stored in the resonator and its transfer to the controlling input voltage port of the transistor. The proposed method has been applied to two experimental oscillators setups with pseudomorphic high electron-mobility transistors. A state-of-the-art phase noise of -50 dBc @ 10-Hz offset from carrier with a 1/f(3) slope has been measured at room temperature with a 9. 2-GHz oscillator. The efficiency of this design method and its ease of use represent, in our opinion, a real breakthrough in the field of low-noise tr ansistor oscillator circuit design.