Theory and design of low phase noise microwave oscillators

Linear oscillator theory is examined to show circuit relationships and limitations. Results from nonlinear analysis are presented that show contributions of second- and third-order nonlinearities to oscillator performance, particularly those of phase noise origin. Results are given for several actual oscillators. Indirect methods of evaluating expected phase noise performance are examined, including second harmonic level, DC, current shift between oscillating and nonoscillating conditions, and extinction frequency, which is the shift in oscillation frequency as the DC supply voltage is reduced from normal levels to the level at which oscillation ceases