Question about high pass filtering

112213

My original signals are all above 0V. I want to filter out signals below 10K and keep signals above 10KHz. How should I do this? I can't do it with RC and RL high-pass filters.

maychang

At least, post your circuit that [cannot achieve high-pass filtering using both RC and RL] and everyone can analyze why it cannot be achieved.

maychang

After posting your high-pass filter circuit, you should also explain what conditions occurred during the test that led you to conclude that [neither RC nor RL high-pass filtering can be used].

qwqwqw2088

Or tell me the resistance and capacitance parameters, such as R in Ω and C in uF.

The cutoff frequency of the high-pass filter can be calculated
or simulated

112213

Although RL high-pass filtering and RC high-pass filtering can play a filtering role, they will lower the overall voltage by 2V. I want to keep the high frequency output as it is. Is there any other way except to re-apply the bias to raise it?

Red is the original signal 14.5K, green is the filtered signal, RC cutoff frequency 12K, RL cutoff frequency 10K. After changing to 1KHzd original signal, it can play a filtering role

maychang

112213 Published on 2024-1-26 11:43 Although RL high-pass filtering and RC high-pass filtering can play a filtering role, they will lower the overall voltage by 2V. I want to keep the high frequency output as it is, in addition to re-...

Your RC high-pass filter has a cutoff frequency of 12kHz and an input signal frequency of 14.5kHz. The input signal will of course be attenuated to a certain extent. The high-pass filter will not attenuate if the frequency is higher than the cutoff frequency.

gmchen

112213 Published on 2024-1-26 11:43 Although RL high-pass filtering and RC high-pass filtering can play a filtering role, they will lower the overall voltage by 2V. I want to keep the high frequency output as it is, in addition to re-...

Yes, only the original DC component can be added.

The function of a high-pass filter is to filter out all signals below the cutoff frequency, including DC.

To maintain direct current, theoretically only a band-stop filter can be used to filter out the part above direct current and below the cutoff frequency. One structure of a band-stop filter is the superposition of the outputs of two filters (one high-pass and one low-pass).