Linked Questions

0 votes
3 answers
7k views

Python- FM Modulation

I am trying to Frequency modulate a sine signal using Python. I have written the following code that should do it: ...
yarin Cohen's user avatar
1 vote
2 answers
7k views

How can I plot the frequency response on a bode diagram with Fast Fourier Transform?

Assume that we have an unknow dynamical system and we only want to estimate its parameters. The system can be discribed as: Continous time: $$G(s) = \frac{3s + 5} {5s^2 + 3s + 2}$$ Discrete time ...
euraad's user avatar
  • 405
2 votes
2 answers
2k views

Can the instantaneous frequency be always derived from an analytic signal?

Instantaneous frequency can be defined as a derivative of an instantaneous phase of an analytic signal which can be nicely seen in practice in this example from Scipy's documentation. But it seems ...
mac13k's user avatar
  • 247
2 votes
1 answer
2k views

Why does frequency sweeping double the frequency?

You can generate a signal with frequency f with sin(2*pi*f*t) where t is time. Yet, when I ...
Aravind Voggu's user avatar
1 vote
2 answers
856 views

The FFT of a sine wave with varying frequency and constant amplitude does not show a plateau, why?

I want to use python to see what the audio response of a speaker is. This would be done by comparing the output of the speaker measured with a microphone to the given input. That means that for both ...
Tido's user avatar
  • 13
0 votes
2 answers
2k views

Phase of the chirp signal

I'm having a tough time understanding the phase increments which are quadratic in nature in the chirp signal. When I see consecutive samples, what will I see in terms of phase and if I have to measure ...
Amu's user avatar
  • 11
5 votes
2 answers
279 views

Nyquist frequency isn't working

The situation is that I have a signal with linearly increasing frequency, $$\text{sin}(2\pi\omega(t)t),$$ where $\omega(t)=a+bt$ for some $a$ and $b$, and we constantly sample at one point per second ...
CoolMathsGuy's user avatar
0 votes
1 answer
1k views

Equation of wave in Linear frequency modulation?

We know that we have the following equation for wave. $$g(t)=A\cos(\omega t+\theta_0)=A\cos(2\pi ft+\theta_0)$$ The equation of frequency with respect to time will be: $$f(t)=\frac{Bt}{\tau}+f_c-\...
Sepideh Abadpour's user avatar
1 vote
2 answers
492 views

Can someone help me with chirp signal generation using direct digital synthesizer(DDS) in verilog?

I want to generate linear frequency modulated (LFM) waveform or a chirp signal using DDS in verilog. I am not using DDS IP Core. I have created DDS module using 8-bit rate counter, a 12-bit address ...
halomi's user avatar
  • 23
2 votes
1 answer
330 views

Designing a Chirp in the Frequency Domain

I am trying to create a chirp signal in the frequency domain, by simply setting the magnitudes of each frequency bin to one, and then setting the phase delay function such that the resulting time ...
Leccy PW's user avatar
0 votes
1 answer
274 views

Obtaining an IR from a sine sweep without the dry sweep

I have a test vinyl record that includes an exponential sine sweep as one of the tracks. I have a recording of the sweep through my turntable/mixer, and now I want to calculate the system IR. The ...
fshstk's user avatar
  • 1
0 votes
2 answers
168 views

Chirp after T seconds

Suppose we have this signal from this wiki page $a(t)=\sin(\varphi_o + f_0t + (f_1-f_0)t^2/T)$ The article tells that T is a period of chirp modulation in which frequency changes. So my question is ...
lisichka ggg's user avatar
1 vote
2 answers
101 views

Frequency slows faster when it's decreasing

I'm sure there's a simple explanation but I can't discover it. Consider two frequencies, a and b. a is higher than b. I can create a wave with both frequencies. But when I create a wave with frequency ...
amd1972's user avatar
  • 21
1 vote
1 answer
120 views

Quadratic Chirp Generating Little to No Effect

I am trying to implement a quadratic chirp on a gaussian pulse which has a 4 ps fwhm. I convert the pulse to the frequency domain using an fft and then encode a chirp with the following function: <...
user68185's user avatar
0 votes
1 answer
105 views

Frequency response of discrete PT1 in MATLAB

I want to calculate the frequency response of a discrete PT1 system with T=T1 and K=1. (the code is at the bottom of the question) To validate the magnitude response, I want to use an sinusoidal input ...
theNewOne's user avatar

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