# Relation between signal mixer and filters

Mixer output shown as red wave:

Can a band-pass filter be used to remove the low frequency shown as a blue sine wave and leave the rest high frequency just like the frequency shown as a green sine wave? If so, which band-pass filter provides the most proper output (most relatable with the green wave?) RC or RLC filters? Active or passive filters?

I want the filter to be compatible with 2 different frequency values to distinguish frequency-modulated waves while showing high impedance to lower or higher frequencies.

An RC bandpass filter outputs a low voltage of the red sine wave if I'm not mistaken

• Bandpass filter's input - red sine wave
• Bandpass filter's output - green sine wave
• Removed frequency - blue sine wave

The circuit I got the screenshot:

The circuit I am up to:

• Why would you want to do that? Commented Jun 18, 2022 at 22:21
• I think it is good if you tell: 1. how much do you know about what exactly is bandpass filter. 2. What is the difference between active and passive filter. I think if you understand this two question then your problem will solve, am I right? Commented Jun 18, 2022 at 22:24
• The red signal is not the sum of the blue and green signals. So, removing the blue signal from the red signal will not leave the green signal. Commented Jun 18, 2022 at 22:32
• bandpass filters can be used to block undesired frequencies if the pass-band of the filter is narrow enough. However, as I mentioned, the red signal is not the sum of the blue and green signals. So when you pass the red signal through a bandpass filter, the result will not be the green signal. Where are you getting these signal images from? Commented Jun 18, 2022 at 22:37
• Deleted cause I wanted to ask a new question electronics.stackexchange.com/questions/624113/… Commented Jun 18, 2022 at 23:00