Comments on "Oscillator with Odd-symmetry characteristics Eliminates Low-Frequency Noise Sidebands

The subject paper [1] concluded that the elimination of even-ordered nonlinearity in an oscillating system would prevent the transfer, of low-frequency flicker noise up to the oscillation frequency zone. This communication is a response prompted by the question: if such a simple expedient as achieving odd symmetry in an oscillator can eliminate
1/f
phase noise, why is it that all oscillators are to some degree corrupted by flicker noise? The significance of the experimental method employed in [1] to demonstrate the desirability of achieving odd symmetry is questioned. Finally, some additional factors relating to oscillator flicker phase noise generation are considered.