T
Tom Bruhns
- Jan 1, 1970
- 0
Anyone have any favorite circuits for accomplishing a variable phase
shift which is relatively independent of frequency? What I'd like:
o Logic level input; logic level output
o Input is square wave between about 2MHz and 120MHz
o Output is two channels, same frequency as input, whose
relative phase may be adjusted over 360 degrees minimum
(-180 to +180 OK too; just need 360 span)
o Output same logic levels as input, nominally.
o Ideally, the phase will be controlled through an analog
voltage input, say 0-5V, but could be different.
It's obviously relatively easy to generate variable delays which are
essentially independent of frequency, but the resulting phase shifts
then depend linearly on frequency. I'd like the phase shift to be
nearly independent of frequency. You can also pretty easily make
phase shift networks that provide a constant frequency-independent
relative phase shift between two channels, but I need the phase shift
to be controllable. I have some ideas about how to do this, but
figured there may be some standard easy way that I'm missing.
Cheers,
Tom
shift which is relatively independent of frequency? What I'd like:
o Logic level input; logic level output
o Input is square wave between about 2MHz and 120MHz
o Output is two channels, same frequency as input, whose
relative phase may be adjusted over 360 degrees minimum
(-180 to +180 OK too; just need 360 span)
o Output same logic levels as input, nominally.
o Ideally, the phase will be controlled through an analog
voltage input, say 0-5V, but could be different.
It's obviously relatively easy to generate variable delays which are
essentially independent of frequency, but the resulting phase shifts
then depend linearly on frequency. I'd like the phase shift to be
nearly independent of frequency. You can also pretty easily make
phase shift networks that provide a constant frequency-independent
relative phase shift between two channels, but I need the phase shift
to be controllable. I have some ideas about how to do this, but
figured there may be some standard easy way that I'm missing.
Cheers,
Tom