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.

503 questions
Filter by
Sorted by
Tagged with
61 views

FFT Amplitude and FFT Bin Averaging

It is my understanding that for FFT (or DFT) returns a single amplitude per frequency bin. e.g., If the frequency bin size is 20Hz, the FFT tells us whether there are 0Hz, 20Hz, 40Hz,60Hz,...frequency ...
47 views

Unbalanced binary sequences for system identification?

I have a physical system that I'd like to obtain the frequency response for. I can only provide binary sequences as inputs to the system. Normally, I'd use a MLS (maximal length sequence) and ...
• 203
1 vote
54 views

Signal response amplitude depends on the time interval in simulation

I have already tried to look for an answer, but I do not find existing answers satisfactory. I am interested in the absolute value of the response function of a damped oscillator (or any time series). ...
18 views

How to compute the 2D coordinate in the s-domain?

I am not sure if my question is a right question to ask or not since I am still learning about Laplace Transform and S-Domain. If we have 2D coordinates (x,y) in the spatial domain (i.e., Euclidean ...
• 163
34 views

Frequency decomposition of forecast error variance

I think my question concerns statistical signal processing. I was referred to this site by a user at Cross Validated. I want to do a frequency-domain decomposition of generalized forecast error ...
1 vote
87 views

Trying to replicate results from tfestimate function in Matlab

I have been trying to replicate the results from the tfestimate function in Matlab by performing, from my understanding, the corresponding signal processing steps in a separate Matlab script file. The ...
94 views

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.
• 185
32 views

Frequency response

in 2.104 he put a condition that x(t) must be an exp to use this result ,but in 2.108 he did't even know what the value of x but use the result to get y i know that he decompose x(t) to group of exp ...
251 views

Phase response of non-symmetric FIR filters

FIR filters are said to have linear phase when the filter coefficients are symmetric or antisymmetric with respect to time instant n=0. I am trying to design a ...
• 325
159 views

Bandwidth of a complex pole

Text from "Fundamentals of Speech Recognition (Rabiner)". A complex pole of the LPC model spectrum can be expressed as $Z_i = > r_i \cdot e^{j \omega_i}$, where $r_i$ and $\omega_i$ are ...
1 vote
116 views

What duration of a white noise burst is required for it to be "white" at a given frequency or frequency range?

I am running white noise bursts (with very short ramps on/off to prevent discontinuities) through underdamped resonant bandpasses which are tuned to any given $f_0$ and an underdamped $Q$. Continuous ...
• 533
53 views

What is the expected amplitude of the flat frequency response of a Kronecker delta function? Does sample rate affect it?

I was instructed here: In the sampled-time domain a Kronecker delta, $\delta(n)$, has a perfectly flat spectrum. If you look at a table of discrete-time Fourier transform pairs, this is at the top ...
• 533
68 views

What happens to the frequency response as a single sample Kronecker delta impulse widens into a square pulse, and then into two distinct steps?

1) Kronecker I was instructed here that a single sample Kronecker delta unit impulse function (goes from 0 to $A$ to 0 again in single sample) has a white noise type frequency response - all ...
• 533
1 vote
103 views

Turning non-symmetric filter into a symmetric filter

I would like to ask if there is a systematic way to turn a non-symmetric filter into a symmetric equivalent with the same frequency response. For example, let's say I have a finite length filter with ...
• 13
1 vote
94 views

A filter that decays proportionately to the wavelength of each freq? So for each wavelength at each freq, that freq's amplitude is attenuated by (*c)?

I am trying to design a filter that decays amplitude of signal passed through it proportional to the number of wavelengths that pass at that frequency in a given time. In other words, where for every ...
• 533
29 views

Cutoff Frequency Calculation for Basic Multimode / State-Variable Filter

I am working with a basic multimode / state-variable filter topology which combines highpass, lowpass, and bandpass outputs. I am wondering if there is a formula I can use to calculate cutoff ...
193 views

• 15
108 views

Finding the impulse response between two microphones

I have made recordings of a single source (musical instrument) with multiple microphones and in the interest of limiting the size of the final project, I would like to find a way to get the impulse ...
113 views

low shelving filter frequency response diagnosis

I am building a second order modified biquad filter based on an implementation by Will Pirkle in "designing audio effect plugins in c++". However when I look at my implementation's ...
• 133
49 views

Characteristics of linear systems in the time and frequency domain

Why is the output signal obtained through frequency response different from the other two. ...
99 views

Finding phase of frequency response as a function of frequency

I am trying to calculate manually the phase of the frequency response of an LTI system as a function of frequency and plot the results. The original system is described as $y[n]=0.1(x[n]-x[n-1]+x[n-2]$...
1 vote
119 views

IFFT caused inverted phase

I've created ifft of signal: Wf=[0 zeros(1,19) conj(W) zeros(1,6000) flip((W)) zeros(1,19)]; w=real(ifft(Wf)); Now take a look ...
207 views

How to find Gain when i have frequency of input and output signal

I need to find the bandwidth of an filter, for this im generating frequency of 1Hz to 200 hz in step of 1hz from a function generator Im expecting -3db point anywhere between 1 and 200 The output of ...
• 21
1 vote
57 views

Simulate Op-Amp low-pass transfer function in Python

I am struggling to simulate the frequency response of a simple op-amp low-pass transfer function in Python. The results I get are not accurate. The transfer function is $H(s)=\frac{1}{1 + s\tau}$, ...
• 423
274 views

How to determine the nature (real or complex valued) of a signal?

A signal X(t) is a real valued time domain signal and Y(t) is a signal that only contains the non-negative spectral components of X(t). How do I determine whether Y(t) is real-valued or complex? I ...
709 views

203 views

Why is an imaginary part in the output of my time-domain resposne of real input?

I have measurements of a transfer function $H(f)$ in the frequency domain between 1-6 GHz. I also have an input signal, which is pulsed chirp $x(t)$. The goal is to build the time-domain response of ...
102 views

Real & Imaginary part of the frequency response of LTI system

I am looking at the H(f) which is the frequency response of an LTI system. What kind of relationship should I expect between the real and imaginary part of this frequency response? Here is an example ...
126 views

How to process a signal in frequency domain then convert it bakc to time domain?

Maybe a example of coupling effect in frequency modulated continuous (FMCW) radar will be helpful to better demonstrate my problem. Let us consider a FMCW radar system. We have a complex transmitted ...
• 155
1 vote
106 views

Scenarios where Phase Response is (non-)problematic

In order to get a better feel for phase response and how it applies across the field of dsp, I'm looking for example scenarios where a filter's phase response is a concern and where it is not. Take ...
• 154
1 vote
117 views

visualizing frequency and phase of a system's response to an impulse

Given a .wav file that is a LTI system's response to an impulse, what would you recommend as the simplest way to plot the frequency and phase output of the system? I'm already working in Python, so ...
386 views

Frequency-domain deconvolution

I want to estimate the impulse response of an LTI system using frequency-domain deconvolution. Suppose that the input signal $x[n]$ of length $N$, and the unknown system impulse repsonse $h[n]$ of ...
• 527
1 vote
208 views

Possible error when finding group/phase delay in scipy

After designing a "least square optimal" FIR filter I wanted to find the group/phase delay, defined as: $P(\omega) \triangleq - \frac{\Theta(\omega)}{\omega}$ (Depending on the literature ...
• 13
For the following system: We have: $$r(t) = s(t) + Ks(t-\tau)$$ where $|K|< 1$, with the following impulse response $h(t)$ and frequency-response $H(f)$: $$h(t) = \delta_0(t) + K\delta_0(t-\tau)$$ ...