16 questions linked to/from Simulation of a Frequency ramp
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: ...
• 169
1 vote
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 ...
• 405
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 ...
• 247
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 ...
1 vote
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 ...
• 13
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 ...
• 11
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 ...
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-\...
1 vote
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 ...
• 23
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 ...
• 23
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 ...
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 ...
• 103
1 vote
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 ...
• 21
1 vote
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: <...