Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

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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Meaning of 'Bessel Filter'

Question I'll get straight to the narrow point ahead: I'd like an expert's opinion on the appropriate use of Bessel when considering a specific 4th order bandpass design. I don't mind a more general answer, so long as I can directly make deductions…
jonk
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Why is superheterodyning better than direct conversion?

What is the advantage of having the extra stage of IF, extra local oscillator and extra filtering stage and amplification. It just seems like more work and circuitry. Surely the direct conversion to baseband and the intermediate conversion to…
Lewis Kelsey
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Two bandpass filters in series, why use different voltage dividers?

I know my question is a bit broad, but I want to ask: Using the single supply configuration, why does the first stage's non-inverting input and second stage's non-inverting input use different voltage dividers, the first one being: 200k ohm and 100k…
poopsalot15
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Derivation of the transfer function of a 5th-order Butterworth LC bandpass filter

I am trying to derive the transfer function of a 5th-order Butterworth LC bandpass filter as seen in the first image. Rs is the source impedance of a signal generator and RL is where a load will be connected. The difference between the first and…
Hendri
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How to generate this kind of filter?

I've been trying to understand this exercise proposed by my teacher. He asked us to find a combination of 2 ideal filters to generate a filter within the conditions of the image below. (That means, band-stop,band-pass,low band and high band) That…
Lucas Tonon
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Designing a circuit from a transfer function

I have this transfer function of a bandpass filter with 2 poles and 2 zeros: $$ H(s)= 10^{-0.8} \frac{\left( \dfrac{s}{10} +1 \right) \left( \dfrac{s}{100.000} +1 \right)} {\left( \dfrac{s}{100} +1 \right) \left( \dfrac{s}{10.000} +1 \right)} $$ I…
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"Top coupling" in VHF bandpass filter

I am looking at a filter design in the ARRL handbook for radio communications. It is a bandpass filter designed to pass 144Mhz with a bandwidth of around 12Mhz. The solid line represents a shield to prevent "stray coupling". \$ C_{c} \$ is a…
Hunter Akins
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Is it possible to design a compact antenna for detecting the presence of 50 Hz mains voltage at very short range?

I have a mains cable buried in the wall. I would like to permanently place a small battery powered device on the wall over the cable's location and have the device be able to detect if the cable is live at any time. Direct access to the cable is…
Wossname
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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 transimpedance amplifier and a bandpass filter to get…
Walter Nazarenus
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What are the differences between active bandpass filter topologies?

I want to use a narrow band active bandpass filter but I found generally 2 topologies as seen below. What are the differences between them?
mehmet
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Designing an audio amplifier, problems with bandpass filter

I am trying to build a Audio amplifier for a university project, I think that most of my circuit is done but I have an issue with my filter as my sine signal is not symmetrical after filtering to eliminate the offset, Instead of having an interval…
Julanu
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Twin-T filter decay rate (drum circuit)

I'm building a Twin-T active bandpass filter as shown on this schematic: simulate this circuit – Schematic created using CircuitLab My aim is to build a simple drum-like synthesizer that rings at a stable frequency sinusoid, when you give it an…
abnutzer
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Picking the right opamp

I've been designing some active bandpass filters and, while in simulations it works great with ideal op amps, I'm not sure how to go about picking an op amp from a distributor. Obviously there are an uncountable amount of options when it comes to…
Zearia
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Order of the filter

I can't seem to figure out the order of the filter. With the knowledge i have, "The order of the filter depends on how much change there is in the (20x)dB/decade in the amplitude response." If it was a addition of 20dB/decade i would understand.But…
Hilton Khadka
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Why is center frequency of a bandpass filter is given by the geometric average of the two cutoff frequencies?

In electronic communication systems, there is a concept called center frequency. A bandpass filter has upper cutoff and lower cutoff frequencies. Center frequency supposed to be in the middle of these. Why is the center frequency of a band-pass…
user16307
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