Dear Dr.

Akram el

Greating!

You can see the following links may be useful to answer

https://www.analog.com/en/analog-dialogue/articles/phase-response-in-active-filters-2.html

https://electronics.stackexchange.com/questions/181190/how-can-i-improve-the-response-time-of-a-low-pass-filter

https://dsp.stackexchange.com/questions/28750/why-do-low-pass-and-high-pass-filters-generate-a-phase-shift

https://www.electronics-tutorials.ws/filter/filter_2.html

https://www.allaboutcircuits.com/technical-articles/low-pass-filter-tutorial-basics-passive-RC-filter/

https://www.allaboutcircuits.com/technical-articles/how-to-low-pass-filter-a-square-wave/

https://en.wikipedia.org/wiki/Low-pass_filter

With best wishes

Adding to Aparna, there are four standard filter functions to construct the low pass filter. These are the: the butterfly, the chebychev, the elliptic and the Bessel filter.

The Bessel filter is the that filter with most linear phase response and constant group delay filter. So, if you want to design linear phase you use the Bessel function filter.

This is for analog filters.

For digital filters you use symmetrical FIR filters. They are characterized by linear phase. But you need an A/D and D/A converter.

When you google you can fined many literature and tutorials about these filters.

Best wishes