# Questions tagged [band-pass]

Bandpass is an adjective that describes a type of filter or filtering process; it is to be distinguished from passband, which refers to the actual portion of affected spectrum. Hence, one might say "A dual bandpass filter has two passbands." A bandpass signal is a signal containing a band of frequencies not adjacent to zero frequency, such as a signal that comes out of a bandpass filter.

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### Designing bandpass filter for audio amplifier

I am a 3rd year engineering student currently working on a project where I need to basically make an ultrasensitive metal detector. Basically, I need to create an alternating magnetic field by ...
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### Is the system linear, time-invariant and causal? Does the decomposition property hold? Sallen Key bandpass filter

I have this ordinary Sallen Key bandpass filter: - simulate this circuit – Schematic created using CircuitLab I'm being asked, if the system is linear and/or time-invariant and/or causal. ...
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### Band-pass op-amp structure with parallel diodes in feedback?

It's been a while since I've done analog circuit theory, and I'm trying to interpret the 2nd gain stage sub-circuit in this schematic for a guitar pedal: I'm not sure if I'm approaching the circuit ...
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### RLC band pass filter — getting the correct phase

Consider the RLC band pass filter circuit: I’m trying to construct this circuit with a maximum of the transfer curve at $f=5-6$kHz and bandwidth $\beta=2\pi \cdot 2$kHz and so I have chosen a 88k\...
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### Coupled Line Bandpass Filter

I am trying to design a microstrip bandpass filter in ADS with a center frequency of 2.4GHz and a fractional BW of 10%. My results from the schematic look great: When I move to the layout and EM ...
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### Filter Q factor with 4 pole filter question

I am designing something related to a vocoder and I need 10 filters with certain specifications and I am confused about the required Q factor. The specifications of the 10 filters that are needed are ...
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### Why do 2 different online active filter calculators give way different GBW requirements for the same frequency range?

I am confused about 2 different online active filter calculators giving different GBW requirements for the same frequency range. One calculator is giving GBW requirements in the kHz range while the ...
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### How does this notch filter work? [duplicate]

I am trying to learn filters. In the following circuit, the author says that negative and positive feedback are used. I couldn't understand what the circuit parts do. Actually I got the negative ...
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### Variable band-pass filter for splitting audio signal into separate signals (high and low freqs)

I've been wondering for quite some time how to create a sort of audio splitter. The idea is to get an audio signal (e.g. guitar) at the input, and have two separate outputs, one with the input's low ...
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### Detect an IR signal with a photodiode to use it with a microcontroller

I am trying to detect an IR signal with a photodiode to connect it to my STM32F411 and use it as a trigger signal. The signal I send are two pulses at 500 kHz which looks like this: I am using a ...
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### Bandpass filter obtained by complementary transformation of lowpass Sallen & Key: what went wrong?

I am considering the following lowpass Sallen & Key filter: My components are the following $R_1=10 k\Omega$ $R_2=10 k\Omega$ $C_1=150 nF$ $C_2=1.65 nF$ Now I have performed a ...
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### Can I change a frequency band of an EQ board?

Is it possible to change one of the frequency bands of this EQ board? In particular, the low frequency adjuster is 100Hz and I want to make it 60ish Hz. My understanding is that i need to meddle with ...
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### Why won't the bandstop filter work in this circuit?

This is the EMG circuit I designed. The cut off frequency of the bandpass is 20-3k Hz. This somehow worked already. But the bandstop filter doesn't show. Why is this? This is the freq-vout graph and ...
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