# Questions tagged [filter-design]

Fiter design is the process of designing a filter.

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### When does a Window function's sidelobe level become out of band attenuation?

Another question I'm struggling to answer by myself. For a Window function, say Blackman (response pictured), what is the out of band attenuation? If I'm designing a filter with out of band ...
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### What is the meaning of a inner system/transfer function?

In an academic paper I'm currently reading [1], the notion of an inner system is central. It is defined as follows A (linear) system $G$ (with $m$ inputs and $p$ outputs) is called inner if it ...
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### Filter response is changed according to its order

I want to build a band-reject filter for the 60 Hz noise. So, I tried to use Butterworth filter to implement this specification. However, when I chose an order of 8, I got the following response, ...
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### Properties of Optimization Techniques in Filter Design

I have this design: Can you tell me about the type of filter and the algorithm just viewing this design, or should there be other information?
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### Least Squares Approximation for FIR Filter Design

Following this paper , I am trying to make a least-squares algorithm in MATLAB, but for type I (I know about firls()). ...
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### Applying Jake's remez exchange algorithm for filter design

I have found C implementation for remez exchange algorithm(https://github.com/janovetz/remez-exchange/blob/master/remez.c) and I want to use this to implement a generic prototype lowpass filter. ...
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### Is there a $z$-transform like for variable sampling rate signals?

I'm working with signals with variable sampling rate (the time space between samples is not constant). I know the delay between samples but I don't wont to interpolate the signal. Is there a way to ...
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### Determine proper coefficients for the transfer function

The problem says that we have the information (actually a .mat file that contains the data) of 1 pixel from an IR camera from an object with 26° of temperature. Because of the noise, the output is ...
353 views

### DWT versus band-pass filter

Which technique gives better result in extracting a band from a signal, let's say the alpha band (8-13 Hz): using a band-pass-filter or a DWT (Discrete Wavelet Transformation)? P.S.: I am working in ...
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### Frequency Translation in MATLAB

I have to design a generic baseband filter. I have a C++ code which gives me filter coefficients based on the input parameters such as no. of taps, no. of bands, band edges, amplitudes and weights(...
428 views

### Looking for a simple and effective notch filter

I ran a finite-difference simulation and the behavior of an output signal, $s$, in time, $t$ (sampled with period $\Delta t$) behaves approximately as in the figure below. It is well-described by a ...
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### Is initializing a digital filter's output with no “momentum” a non-trivial task?

I'm working on implementing a filter with a very slow step response. This filter is implemented as a cascaded second-order-section filter (transposed direct form 2). I'm using the output of this ...
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### Is there anything called uncorrelated filter?

I understand to an extent various filter like low pass filter, high pass filer, Wiener filter Kalman filter etc. I also understand some of this filter will decorrelate/uncorrelate the signal. The ...
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### can $\frac{1}{H(z)}$ be causal and stable? [duplicate]

if we have linear phase FIR filter $H(z)$ which is causal and stable can $\frac{1}{H(z)}$ be causal and stable ? can it be causal without been stable ?
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### Speaker equalization for white noise

I need a speaker to play broadband white noise for my scientific application. I would like to know whether my relative naive implementation is correct or not. The speakers I use have a large frequency ...
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### Derivative filter in Python

In Alaa Kharbouch, Ali Shoeb, John Guttag, Sydney S. Cash, An algorithm for seizure onset detection using intracranial EEG, Epilepsy & Behavior, Volume 22, Supplement 1, 2011 (section 2.1, 3rd ...
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### Signal filtering using Python

I'm trying to create an application using python that is capable of recording an audio signal and detecting short glitches in the signal. For example, I could be recording a 1000Hz sine wave and ...
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### Whats is the difference between FIR/IIR filters and Chebyshev/Butterworth filters

I am new to Signal Processing. From my understanding -- FIR/IIR just refer to the placement of poles and zeros in the z-domain helping us achieve convolution, if FIR and ??? in IIR. Chebyshev and ...
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### Downconverting real signal to IQ baseband

Despite reading various answers on this site and on other sites I am still confused about how to convert a real-valued signal back down to its original IQ baseband values. Note I am still a beginner ...
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### 1st order filter output

Two 1st order filters : ...
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### Design narrow bandpass filter for signal with high sampling rate

I have to bandpass-filter a signal which has been sampled with 4000 Hz. Only frequencies around 15 Hz shall remain after filtering (let's say in a band between 10 Hz and 20 Hz; the narrower the ...
44 views