Digital Filtering Query

Thread Starter

BUZZARD1n

Joined Apr 20, 2022
24
Good day everyone,

I am pretty new to digital filtering and AM modulation, and demodulation in general. I have designed and constructed an analogue AM modulator/demodulator, and I have recently designed a digital filter (FIR). My goal, however, is to make an AM demodulator using the STM32F429. I plan to use my analogue AM modulator to feed an AM signal to the ADC (Planning on interleaving ADCs) of the STM32. After that, I want to use a digital filter to allow me to select a particular frequency channel and filter out the rest within the AM band ( 535.5 kHz to 1606.5 kHz ). But unfortunately, this is where my thought of the process fades. I understand that a bandpass filter allows one to select a specific frequency range to pass (Passband between shoulder frequencies FL and FH), but how would one approach a situation where one would want to select a channel at every 9 kHz, for example. Would one use multiple bandpass filters for every channel (120 bandpass filters in this case)? Or would one build a type of bandpass filter that adjusts for every 9kHz to the change of the AM signal's frequency? Thank you for everyone's input and time.

Greetings,
Ryan
 

crutschow

Joined Mar 14, 2008
30,143
What part(s) will you use to implement the digital filter?
Typically you would just program the digital filter to select the frequency you want to detect.
 

Thread Starter

BUZZARD1n

Joined Apr 20, 2022
24
What part(s) will you use to implement the digital filter?
Typically you would just program the digital filter to select the frequency you want to detect.
I am planning on programming a FIR bandpass filter to select the frequency. I guess I am just lost about how one would go about making a bandpass filter to allow multiple channel selection. I am still doing research regarding the best appropriate digital filtering technique.
 
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