# Questions tagged [phase]

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72 views

### Why do FIR linear interpolators have linear phase?

I wonder why linear interpolation is a linear-phase FIR filter. In fact, I am reading Dr. Rice's great book "Digital Communications; A Discrete-Time Approach," and he mentioned on page 466 ...
111 views

### What is phase shift?

I'm reading about when a $H(z)$ system is min phase or max phase, and I get when a system is a min phase or max phase depending on the location of the zeroes. But I don't get at all the phase shift ...
15 views

### Imaginary part of dispersion relation

Let's suppose that I have defined Real dispersion relation (f, Rek) and a imaginary dispersion relation (f, Imk). Reading simply wikipedia the group velocity takes into account only the Real part: &...
78 views

### Extraction of the phase lag form cross-correlation function

I would like to find out the phase offset that my signal contains at the receiver side. For this, I use the cross-correlation function, where I cross-correlate signal before and after matched filter. ...
93 views

### Stability of filters with negative phase delay, group delay, and positive phase

Lets assume I have an IIR filter with : bz = [1.0195 0 0]; az = [1 0.0166 0.0020]; fvtool(bz,az) The filter is stable as i can see. If you check the phase delay ...
141 views

### phase offset extraction using matched filter

I'm looking for an application of detecting the drift of a received signal carrier frequency from ADC clock of the receiver (in case of no drift, ADC clock should be optimally an integer multiple of ...
32 views

### Recovering phases of a sum of sinusoids using a DFT

I generate data in the following way: \begin{align} x_n = \cos\left(\left(\frac{2\pi}{100}\cdot 1\right)n + 0.8\right) + \cos\left(\left(\frac{2\pi}{100}\cdot 2\right)n + 0.6\right) + \cos\left(\left(\...
95 views

### Why does my PLL simulation oscillate after locking?

I'm working on a crude circuit simulator with the goal of implementing PAL encoding and decoding, so that I can experiment with generating images that look like video transmissions. In the simulation ...
81 views

### Phase Noise and Multi-carrier Frequency conversion

I have a oscillator with a phase noise mask that was represented in dBc at specific offsets from a carrier. Two options for a multicarrier signal going into a converter, apply the phase noise mask (...
41 views

### converting complex sum of exponential signal to real signal

I have the following Signal model, that generates a discrete-time complex signal, where $a_k$ - amplitudes, $\phi_k$ - phases, $\alpha_k$ - damping factors and $f_k$ - frequencies are the parameters ...
26 views

### Identifying a signal by its power spectrum

Background: There is a method in optics for determining the electric field of light (both intensity and phase) via a three step process: Add a known phase shift to the light (called the "...
132 views

### Getting a single feedback peak from a basic 4 stages phaser

I try to set a very basic 4 stages phaser (two 2-pole all-pass filters), with a particular feedback path where only one peak is raised at center frequency when the feedback is above 0. The following ...
31 views

### group velocity and phase velocity

I am studying group velocity and phase velocity. I would like to have a confirmation if I understood correctly. If the dispersion curve is linear , do the group velocity and the phase velocity ...
50 views

### Phase of the sine signal by finding FFT of it in matalb using angle

I am using sine signal with phase=0 an frequency=100KHz. Computed FFT of it. Using angle function and multiplied the result with 180/pi; But getting 90.36 at 100KHz frequency. Can anybody explain why ...
54 views

### How to calculate the total signal strength and phase shift of multiple signals in a reciever

I have a simulation to make where I have an array of transmitters that transmit the same signal. At a random point, which I have to consider as a receiver I have to measure the phase shift of the ...
3k views

### Understanding the FFT phase spectrum with a simple example

I'm trying to compute the DFT using scipy's functions. I don't understand why the phase spectrum of a simple sine wave with 2 Hz frequency doesn't show $\pm\pi/2$ at the $\pm 2Hz$ frequencies. Instead,...
57 views

### script to check zero crossings to check if microphones phases are aligned

I have 'n' microphones placed in square fashion and I want to make sure that all the channels must be aligned in time exactly the same if the signal is equidistant from all the 'n' microphones i.e. in ...
162 views

### phase difference detection

For application of syncing sampling clock phase to carrier phase of received signal where the received signal is sampled with 10 times the carrier phase and modulated with the PSK shown in the figure (...
127 views

### How to achieve a smoothed frequency phase response with no outliers

I have two sampled signals, which I then perform wavelet analysis on, by synthesising the Filterbank, perform the dft on each kernel, and the dft on the sampled signals, and multiply together. ...
235 views

### Measuring group delay through a linear phase filter

I'm having a difficult time wrapping my head around a phase/ group delay problem and it corresponding to where you start sampling so I built up a system to test some of these issues. The system passes ...
2k views

### Calculating the magnitude spectrum and phase spectrum

From a window function $x(t)=u(t+2)-u(t-2)$, we can get the Fourier Transform $X(j\omega)=\frac{2\sin(2\omega)}{\omega}$. Then, I want to calculate its magnitude spectrum and phase spectrum. The ...
66 views

### Is there a way to break down a signal into its respective phases (4 in this case) to be later analysed individually

Is there a way to extract amplitude information but over 4 phases of the same frequency. That is, if the frequency is known could I extract amplitude peaks (between given values)in the time domain in ...
76 views

### Coherent averaging of polyphase components of a signal

I want to subsample a multi-band signal to introduce controlled aliasing. My frequency components are uniformly distributed across the spectrum (comb structure) and occupy a relatively narrow ...
106 views

### scipy cross-correlation: interpretation

I want to compute the phase shift between two 1-D signals of same frequency, but before I'm trying to compute the time shift between. The cross-correlation function seems to be ideal for that but I'm ...
42 views

### why is my phase spectrum calculated by hand not agreeing with matlab's freqz?

I am trying to replicate the Matlab function freqz. To calculate the phase of the frequency response of my filter I am implementing the equation for phase:  \phi(...
122 views

### Phase measurement with FFT for DMM Keithley 7510

I am currenly working on a measurement driver for the DMM Keithley 7510. I implemented a harmonics measurement using FFT (from MathNet library). First I simply sample my input voltage signal and ...
93 views

### When joining two signals of different frequencies how do I find the phase shift that makes the join smooth?

I'm generating a sine wave and I want the second half of the signal to be in a different frequency. How do I find the phase shift I can apply to the second half so that the joining between the halves ...
2k views

### How to "rotate the phase"?

I have problem, not sure how to call it but I think it's something called "phase rotating", but not sure. I make fast Fourier transform on simply square wave, and then I make inverse fast Fourier ...
78 views

### Is the phase difference between recorded sounds from left and right ear the same as the phase difference between their HRTF?

Pardon my ignorance if my question is silly. Lets say I did a binaural recording and found the phase difference between right and left channel. If the recording was done in anechoic chamber, where ...
42 views

### Varying shift between microphone data

I had given a sine wave of frequency 2kHz as input to two microphones placed near to each other. The data grabbed by two microphones are then plotted in MATLAB and it was found out that the initial ...
48 views

### How to reduce phase noise in radar?

Instability of oscillator can introduce phase noise to the signal received by radar . Are there commonly used digital signal processing methods can reduce the phase noise?  Aubry, Augusto, et al....
23 views

### 1D-Phase Unwrapping

I am new to signal processing and I am reading about 1D phase unwrapping Here is the paper that I am reading https://www.ljmu.ac.uk/~/media/files/ljmu/about-us/faculties-and-schools/fet/geri/...
53 views

### How to get the phase of a 2D sine wave?

I am trying to find the phase of a generic 2D sine wave with the 2D FFT. The formula for the phase is arctan(im/re). So I made 22 sine waves with phases ranging from 0 to 2 pi (by cropping the ...
201 views

### help to calculate phase shift in certain frequency(identified from FFT)

I am designing a 24ghz doppler radar, with 1TX 2RX. Four adc channel are recording at 25khz, applying 256point FFT on adc of both of RX I and Q, I could identify the target in certain doppler ...
71 views

### Phase spectrum interpretation

I have an analog signal alternatively captured by two probes. Sometimes the signal is periodic and depending on the physical conditions the two periodic signals might be in phase or out of phase. Also,...
196 views

### How can you 'perfectly' reconstruct phase for transients in a modified audio absolute spectrogram?

I am currently working on the absolute spectrogram of an input audio signal. I am using non-negative matrix factorization to separate out the rhythmic components (bass drum, snare drum and hi-hat) of ...
230 views

### Phase difference calculation for non divisible sample rate to frequency

I am learning DSP and I am trying to simulate a simple phase difference calculator between two sinusoidal signals using GNU radio. My flowchart looks like this: As can be seen on the chart, one of ...
65 views

### Varying phase shift between two signals

I have two microphones separated by a distance d placed in end-fire configuration. Audio input data was played from the front side (i.e corresponding to 0 degrees.) The data picked by microphone1 and ...
16 views

### Best choice to digitally rotate reference for an IQ filter?

I have analog GHz signal modulated with 60KHz signal and I analog mix it with reference GHz and low pass filter so now I have a 60KHz signal $a$ which I enthusiastically sample (at 1MHz). Meanwhile I ...
37 views

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### Phase Response of $N$-th order Digital All-Pass Filter

I am having trouble reconciling my derivation of the phase response of an N-th order all-pass filter with those I am finding in the literature, and I figured someone here could help me. Real Version: ...
150 views

### Phase of matched filter for chirp signals

I am using the following system: Ultrasonic chirp signals with central frequency 100kHz are being transmitted using ultrasonic sensor. After the transmission through the medium(air/solid/liquid/...