Questions tagged [chirp]
A chirp is a signal class where the instantaneous frequency is monotonically increasing in time.
56 questions
1 vote
1 answer
121 views
Fourier Transform for quadratic chirp
(Tomorrow I plan to start answering this myself) Robert Bristow Johnson in his paper Intraframe time-scaling of nonstationary sinusoids found the fourier transfrom of a ramped ($e^{2 \pi \lambda t}$) ...
- 776
3 votes
3 answers
162 views
FMCW - Chirp bandwidth superior to ADC samplig rate
I was looking at cheap radars like this one and notice that the chirp bandwidth is 4 GHz but the sampling rate of the ADC is 25 MS/s. I know the resolution of such a radar is given by $ \Delta R = \...
- 33
1 vote
0 answers
206 views
Fractional Fourier Transform rotation of a chirp
I'm trying to wrap my head around something I read in a paper: "The Wigner distribution of a linear chirp signal x(t) illustrates how the FrFT (Fractional Fourier Transform) may be used to ...
- 11
1 vote
1 answer
80 views
help me repeat the signal in python
help me repeat the signal in python. The picture shows the signal after CWT analysis. It looks like a chirp 7-17K with some modulation. Thank you.
- 33
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 ...
- 123
4 votes
1 answer
523 views
What wavelength do we use when calculating the array manifold vector when transmitting LFM waveforms?
We know that the array manifold vector, also called the steering vector, for an M element array is given by: $$ \mathbf{a}(\theta, \phi) = [e^{-j \omega \tau_{1}(\theta, \phi)}, e^{-j \omega \tau_{2}(\...
- 652
1 vote
1 answer
198 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: <...
- 11
0 votes
1 answer
223 views
What does it mean to find the steady state output in this case?
I have a given $h[n] = 0.96^n$ for $n \in \{0,1,...,119\}$ and a test signal $x[n] = \cos(0.05\pi n)$ for $n \in \{0,1,...,N_x -1\}$ where $N_x = 120,000$. Now, I can analytically find the output $y[n]...
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