TBH it’s been more than a decade since I graduated electronics engineering, I really didn’t like filter theory, so I went with embedded electronics for my specialization, and went to work in an entirely different field so…
What’s the purpose of this filter, if all you’re getting out is DC? I mean wouldn’t you want to set the cutoff frequency high enough to actually get a signal through? If all you’re looking for is the DC component, then wouldn’t you be better off (as in a more simple, thus cheaper, solution) just doing a rolling average filter?
Again, I really didn’t follow along in signal processing that well, so I may just be exposing my ignorance here.
The (effective) low-pass is only applied after the signals have been multiplied. This filters out the signal with the same frequency (and phase) as the reference. I have a more detailed comment on how this works in response to another person here in this comment section.
This is useful for applications, where the signal can be drowned out by the noise, but you know what to look for, and where the phase information is important. (e. g. a DC signal that is chopped at a selected frequency or an AM-signal).
TBH it’s been more than a decade since I graduated electronics engineering, I really didn’t like filter theory, so I went with embedded electronics for my specialization, and went to work in an entirely different field so…
What’s the purpose of this filter, if all you’re getting out is DC? I mean wouldn’t you want to set the cutoff frequency high enough to actually get a signal through? If all you’re looking for is the DC component, then wouldn’t you be better off (as in a more simple, thus cheaper, solution) just doing a rolling average filter?
Again, I really didn’t follow along in signal processing that well, so I may just be exposing my ignorance here.
The (effective) low-pass is only applied after the signals have been multiplied. This filters out the signal with the same frequency (and phase) as the reference. I have a more detailed comment on how this works in response to another person here in this comment section. This is useful for applications, where the signal can be drowned out by the noise, but you know what to look for, and where the phase information is important. (e. g. a DC signal that is chopped at a selected frequency or an AM-signal).