Great video and nice channel. I haven't had time to watch all your videos on injection locking yet, so apologize if you covered this elsewhere. Here's my question: does Adler's equation hold when omega_inj = omega_0, i.e. the injection frequency is equal to the oscillation frequency? The practical scenario would be if an oscillator is being pulled by it's own output (from another part of the IC that's driven by a buffer, for example). Just setting the frequency difference to zero would reduce Adler's equation to a response due to an initial condition, and it seems to say that the initial phase theta settles to the nearest multiple of 2pi. But in measurements, we see that the oscillator shifts to a different frequency instead (when the output is turned on). What are we missing when applying Adler's equation to describe this case? (Even if allowing for some phase delay between the buffered output and the oscillator's oscillation, we seem to only get a delayed differential equation similar to Adler's, that does not predict a frequency shift either). Thanks you for your answer and comments in advance! And hope to see more from your channel.
When omega_inj = omega_0, yes Adler's equation predicts zero phase shift (2*n*pi to be precise). I don't know the details of your experiment. The load that your oscillator sees could be changing and that could change it's oscillation frequency.
The Adler's problem assumes different frequencies between input and output, does it not? Assuming magnetic coupling, for example, and in the case where the same frequency is present, should we consider the inductive part of the LC tank as changing due to inductive coupling, thus changing the VCO frequency? Nice video, by the way.
Great video and nice channel. I haven't had time to watch all your videos on injection locking yet, so apologize if you covered this elsewhere.
Here's my question: does Adler's equation hold when omega_inj = omega_0, i.e. the injection frequency is equal to the oscillation frequency? The practical scenario would be if an oscillator is being pulled by it's own output (from another part of the IC that's driven by a buffer, for example).
Just setting the frequency difference to zero would reduce Adler's equation to a response due to an initial condition, and it seems to say that the initial phase theta settles to the nearest multiple of 2pi. But in measurements, we see that the oscillator shifts to a different frequency instead (when the output is turned on).
What are we missing when applying Adler's equation to describe this case? (Even if allowing for some phase delay between the buffered output and the oscillator's oscillation, we seem to only get a delayed differential equation similar to Adler's, that does not predict a frequency shift either).
Thanks you for your answer and comments in advance! And hope to see more from your channel.
When omega_inj = omega_0, yes Adler's equation predicts zero phase shift (2*n*pi to be precise). I don't know the details of your experiment. The load that your oscillator sees could be changing and that could change it's oscillation frequency.
The Adler's problem assumes different frequencies between input and output, does it not? Assuming magnetic coupling, for example, and in the case where the same frequency is present, should we consider the inductive part of the LC tank as changing due to inductive coupling, thus changing the VCO frequency? Nice video, by the way.