locked Re: Measuring and matching 10.7 MHz ceramic filters
Radu Bogdan Dicher
toggle quoted messageShow quoted text
After recalibrating - which I'm about to redo, as I'm not 100% sure of all steps - I'm getting this out of a 150kHz filter (JA). I trust I need to recalibrate or maybe the device is subpar?... I'm invariably getting about 5dB lower readings on the left/lower side of the response plot. I'm definitely willing to persist quite a lot, but I'd really love to figure out where the deficiency is...
Here is a wider frequency scan showing, for comparison, the response of both the previous Murata 280 (red) and Murata 150 (black). Note, these are better examples of almost perfect looking filters. They don't all look this good, for frequency or shape. As one can see, the group delay gets very noisy outside the filter passband.