Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [frequency-response]

Frequency response is the quantitative measure of the output spectrum of a system or device in response to a stimulus, and is used to characterize the dynamics of the system.

Frequency response is a measure of magnitude and phase of the output as a function of frequency, in comparison to the input. In simplest terms, if a sine wave is injected into a system at a given frequency, a linear system will respond at that same frequency with a certain magnitude and a certain phase angle relative to the input. Also for a linear system, doubling the amplitude of the input will double the amplitude of the output. In addition, if the system is time-invariant, then the frequency response also will not vary with time.

Source: Frequency response

500 questions
8
votes
2 answers

Why are there comb-like hills in a periodogram?

I am playing with the periodogram of MATLAB. I created a simple script to observe how it behaves: rng(1); %# initialize the random number generator Fs = 1000; %# Sampling frequency duration = 0.1; %# seconds A = 1; %# Sinusoid amplitude f = 150;…
petrichor
  • 235
  • 1
  • 3
5
votes
2 answers

Is it possible to infer the characteristic curve of a recording device only from (many) recordings?

... with a certain degree of confidence / corridor of accuracy. What do I mean? Case in point: There is the huge archive of digitized Edison wax cylinder recordings. They have annotations, usually year of recording, sometimes producer of…
user1847129
  • 153
  • 4
4
votes
3 answers

Frequency response equivalent to characterise transient response (to sinusoidal inputs)?

I am interested in characterising the time-dependent response of a system to a sinusoidal input. The steady state response of the system is also sinusoidal, however I wonder if there is a standard way to represent the information in a manner that is…
xyz
  • 145
  • 7
3
votes
2 answers

Why do we choose cutoff frequency to be taken for "1/sqrt(2) magnitude reduce"?

Why don’t we instead choose (calculate) our bandwidth to be between two purple “dot’s”? Why don’t those purple dot’s represent points for “cutoff frequency”? Looking at this picture “frequency components” after the right purple dot (or before the…
Krushe
  • 135
  • 1
  • 7
3
votes
1 answer

How to measure the frequency response of an acoustic filter by input and output signals

I am trying to measure the frequency response of acoustic filter. I sample the sound before propagation in the filter and after by 2 different mics. And now I am trying to find the system (the acoustic path) frequency response. Using matlab how can…
Anna
  • 51
  • 1
  • 3
1
vote
2 answers

Criteria to compare two frequency responses

I am designing a FIR-low pass filter using freqz function in matlab. I have generated numerator coefficients using one technique(lets call it original response). Also I am trying to come up with these coefficients using some other technique(lets…
MohitGodara
  • 21
  • 3
1
vote
1 answer

What is the relationship of S-parameters to frequency response?

I have some S-parameters. I'm reading about frequency response and the impulse response and step response. If I have a set of S-parameters, then is the frequency response for a port (say output port 2, input port 1) simply $S_{21}$ for all the…
user3239013
  • 13
  • 3
1
vote
1 answer

narrow band frequency response creation and general FR question

i need some guidance with understanding frequency response characteristics. i have the a signal A with is played on speakers and recorded via microphone which is signal B. then i apply a window function, shift both signals to frequency domain and…
Maximilian Körner
  • 289
  • 2
  • 9
1
vote
1 answer

Find the impulse response from the frequency response

So I'm having a problem here which gives me the frequency response and asks for the impulse response: $H(\Omega ) = e^{-j\frac{\pi }{2}}$ for $\Omega>0 $ and $H(\Omega ) = e^{j\frac{\pi }{2}}$ for $\Omega<0$ I need to find the impulse response. My…
Georgio3
  • 11
  • 2
1
vote
1 answer

What does the amplitude in a frequency response of a signal signify?

Well according to my understanding it tells the concentration of signals at a particular frequency but what does the number really mean? Suppose in a frequency response graph i have such a relation :: "a1"(amplitude) at "f1" (frequency) a2 at f2 ,…
Aashwin Gaur
  • 13
  • 2
1
vote
2 answers

What is the Autocorrelation of the Impulse Response if the Magnitude of Frequency Response is >1

So by the DTFT pairs, if the magnitude of the frequency response of a signal is 1, then the autocorrelation is the Kroneker Delta Function. What if I find that the magnitude of the frequency response of the system is greater than one? Is the…
Gary
  • 345
  • 1
  • 4
  • 14
0
votes
0 answers

What kind of filter would produce this kind of frequency response?

What kind of filter would produce this kind of frequency response? I'm pretty sure there's a moving average involved, maybe two, but that's as far as I got.
adr
  • 185
  • 1
  • 6
0
votes
1 answer

can I calculate freq response generically from filters?

I'd like to display the freq response of a Sallen Key filter type (in the specific case, this simple resonant filter). on biquad, for example, I calculate magnitude and phase from zeros and poles, such as (in cpp): // zeros std::complex…
markzzz
  • 45
  • 1
  • 2
  • 10
0
votes
1 answer

How does signal subtraction affect frequency response?

I had a noisy signal which I denoised using machine learning. Now assuming the noise was additive I am subtracting the denoised signal from the noisy signal to get the noise part. I just did time domain subtraction, but when I plotted the frequency…
nasrin
  • 53
  • 2
0
votes
1 answer

frequency response of a time domain subroutine in matlab

I implemented a sigal processing structure using very basic operation like multiply and add, I wonder is it possible to find a built-in function in matlab to treat this as a black box and obtain its frequency response. I imagine the process…
Eagle Shou
  • 149
  • 5
1
2