Phase noise of self-oscillators based on field effect transistors with increased linearity of transfer characteristics
A possibility of reducing the phase noise of self-oscillators based on field effect transistors (FET) by replacing FETs with a homogeneous profile by FETs with special doping profiles providing increased linearity of the transistor transfer characteristics has been considered. Comparative results of low-frequency noise measurements of transistors and the results of modeling the spectral power density of phase noises of self-oscillators based on them are presented. It is shown that even with intrinsic low-frequency noise of the FET with a special doping profile, significantly exceeding the noise of the conventional one, the advantage in phase noise of devices on it, can be about 10 dB. Besides, there is a potential for additional reduction of phase noise by 10 dB during a 10 kHz offset by testing the technological process of manufacturing FET with a special doping profile, which will allow such self-oscillators to reach the level of devices using bipolar transistors.