What is Phase shift: Definition and 140 Discussions

In physics and mathematics, the phase of a periodic function


{\displaystyle F}
of some real variable


{\displaystyle t}
(such as time) is an angle-like quantity representing the fraction of the cycle covered up to


{\displaystyle t}
. It is denoted


{\displaystyle \phi (t)}
and expressed in such a scale that it varies by one full turn as the variable


{\displaystyle t}
goes through each period (and


{\displaystyle F(t)}
goes through each complete cycle). It may be measured in any angular unit such as degrees or radians, thus increasing by 360° or


{\displaystyle 2\pi }
as the variable


{\displaystyle t}
completes a full period.This convention is especially appropriate for a sinusoidal function, since its value at any argument


{\displaystyle t}
then can be expressed as the sine of the phase


{\displaystyle \phi (t)}
, multiplied by some factor (the amplitude of the sinusoid). (The cosine may be used instead of sine, depending on where one considers each period to start.)
Usually, whole turns are ignored when expressing the phase; so that


{\displaystyle \phi (t)}
is also a periodic function, with the same period as


{\displaystyle F}
, that repeatedly scans the same range of angles as


{\displaystyle t}
goes through each period. Then,


{\displaystyle F}
is said to be "at the same phase" at two argument values



{\displaystyle t_{1}}



{\displaystyle t_{2}}
(that is,








{\displaystyle \phi (t_{1})=\phi (t_{2})}
) if the difference between them is a whole number of periods.
The numeric value of the phase


{\displaystyle \phi (t)}
depends on the arbitrary choice of the start of each period, and on the interval of angles that each period is to be mapped to.
The term "phase" is also used when comparing a periodic function


{\displaystyle F}
with a shifted version


{\displaystyle G}
of it. If the shift in


{\displaystyle t}
is expressed as a fraction of the period, and then scaled to an angle


{\displaystyle \varphi }
spanning a whole turn, one gets the phase shift, phase offset, or phase difference of


{\displaystyle G}
relative to


{\displaystyle F}
. If


{\displaystyle F}
is a "canonical" function for a class of signals, like



{\displaystyle \sin(t)}
is for all sinusoidal signals, then


{\displaystyle \varphi }
is called the initial phase of


{\displaystyle G}

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  1. W

    Difficult Understanding Magnitude and Phase Shift of Transfer Function

    Hello, My textbook offers the following transfer function as an example. It then goes on to explain that the following equations represent the magnitude and phase shift of the transfer function. However, I am having some difficulty jumping from the first equation to these equations. From...
  2. J

    Equation that describes positive/negative feedback

    Hi, Curious if there is an expression for a negative feedback system that experiences phase shift. For example, at 0 degree phase shift, the additional gain is 0 because it is fully negative feedback. At 180 phase shift the additional gain is infinite because you have full positive feedback. Is...
  3. N

    I Calculating phase shift between two sinusoidal waves

    Hello, Came across this picture and passage from a textbook. Although the text lays out a method for calculating the phase shift between displacement and acceleration, I am not sure how they are calculating which wave is leading and which is lagging. From their description, it seems like a...
  4. martijn_tholen

    Propane/Oxygen - from Cylinder to Oxy/Fuel cutting torch

    For one of our projects we are at present using quite large amounts of gas & oxygen. What I was trying to figure out was how to calculate the total available amount of gas in a cylinder (be that either Propane/Oxygen or Propylene (Propene)) and then to determine whether or not -given a certain...
  5. Y

    Does wire length difference create phase shift?

    When wiring a 240 volt AC circuit, I've always assumed that it's important for L1 and L2 wires to be the exact same length, in order to avoid introducing a phase shift that would reduce peak voltage. Length differences can accumulate when the wires enter a panel and need to go slightly...
  6. C

    Purely passive RC Phase Shift Oscillator?

    It is possible to build a purely passive RC phase shift oscillator with 2 separate (in the future) RC stages like this? Where there would be 2 RC networks that each provide 180 degrees of phase shift. Of course, there would be a buffer in between the 2 RC networks so that they behave as 2...
  7. S

    I Phase Shift of a Sine Wave

    Hi, I have created a sine wave with the following options: 1.) - changing the period/length in days of the sine wave (Cycle Length in Days) 2.) - calculating the start value of the "dummy" so that the sine wave always starts with -1 (Dummy Start at Cycle Trough) when the phase shift is set...
  8. C

    RC Phase Shift Oscillator not Oscillating

    Hello everyone. I am having some trouble with an RC phase shift oscillator that I built as a hobby project. I am completely stuck on this and I just cannot figure it out. My oscillator is not oscillating. Here is the circuit that I am trying to get to work. Taken from...
  9. R

    180 degree phase shift of reflected light

    When light originating from a medium of lower refractive index reflects off a surface of higher refractive index, why does the phase shift by 180 degrees? Stokes relations show that reflection coefficients at the surface are equal but of opposite signs depending on direction of light (i.e...
  10. dvscrobe

    Aliasing Phase Shift: Determining Phase Shift

    How do you determine the phase shift of an aliased signal?
  11. I

    Phase shift between voltage and current

    Hello ,so am trying to find a phase shift between voltage and current ,I've done what do i do after that ?and is this right ? Q A 100Ω load is connected to a power supply of 100V at 50Hz. At time, = 0, the instantaneous value for voltage across the load was zero and the current through the load...
  12. Francis

    A Conditional phase shift for Grover's algorithm

    I am trying to understand the following deduction: "The conditional phase shift can be represented by the unitary operator 2|0> <0| - I:" for eq. 4a) I was expecting to be: [2 |0><0| - I] |0> = 2 |0> <0|0> - I|0> = 2|0> - |0> = |0> as for eq. 4b I can't understand it at all. Why does the...
  13. phywithAK

    Phase shifts for a localized Coulomb and harmonic potential

    I am struggling over a problem and i could really use some help in this. So it's about finding phase shifts in a localized sphere of coulomb and harmonic potential. I tried solving the radial Schrodinger equation for both of them by using power series method, but still i am having problem...
  14. E

    S-wave phase shift for quantum mechanical scattering

    a.) The potential is a delta function, so ##V \left( r \right) = \frac {\hbar^2} {2\mu} \gamma \delta \left(r-a \right)##, therefore ##V \left( r \right) = \frac {\hbar^2} {2\mu} \gamma ## at ##r=a##, and ##V \left( r \right) = 0## otherwise. I've tried a few different approaches: 1.) In...
  15. nima_kheradhoosh

    AC Variable Phase Shift

    Hey fellas, I’m trying to apply a variable phase shift (0 to 180 degrees) on an AC signal generated from a Variable Frequency Drive (VFD). The frequency is variable and ranged between 10 and 50 Hz. the voltage amplitude is also variable between 10-50Volts (this shouldn’t be a problem I suppose)...
  16. D

    I have tried building a phase shift oscillator, but it won't work

    I built a phase shift oscillator, but it Won't work. I visit the website https://www.google.com/url?sa=t&source=web&rct=j&url=https://en.m.wikipedia.org/wiki/Phase-shift_oscillator&ved=2ahUKEwiV4Y-26OHiAhUClawKHQhACO8QFjANegQIChAG&usg=AOvVaw0YoHKumGz0Xl3fYKtIRdFa and copied the schematic I saw...
  17. S

    B Phase shift in Mach-Zehnder interferometer

    I'm confused by the phase shifts in a Mach-Zehnder interferometer because I keep finding two different explanations. One explanation (for example, given on Wikipedia, but also elsewhere) states that on each reflection, the phase shift is 180 degrees, but only, if light is reflected from the...
  18. AwesomeTrains

    I Help understanding the formula for the total phase shift of a waveplate stack

    I have problems deriving a formula in a paper I'm reading for a project. The paper is about putting a number of waveplates in series rotated relatively to each other to form a tuneable broadband waveplate. For the i-th waveplate the jones matrix is given by: $$ J_{i}(\delta_i, \Theta_i)=...
  19. A

    Understanding Polarization-Dependent Phase Shifts of Radio Waves

    I've seen this video: There it is explained that an electromagnetic (here radio) wave has a phase shift if it was radiated in horizontal polarization, but it does not experience the phase shift when it was emitted vertically polarized when it gets reflected on the ground. When reading up on...
  20. L

    How to introduce a phase shift in an AC circuit

    Hello, I am trying to think of a way to introduce a phase shift in an ac circuit. For example, sin(omega*t+theta) to change theta. How can I go about doing this? I do not think introducing a cap or inductor would work, even though it shifts the voltage from the current graphs (phasors). A...
  21. B

    I Phase shift after double-slit for entangled photons

    Hi all, I'm trying to understand how to describe the quantum state of entangled photons, including their phase, if one of them encounters a double-slit. Here's a simple example: Suppose you have two polarization-entangled photons A and B in the following Bell state: \begin{equation}...
  22. P

    I Grover algorithm phase shift

    Hi everybody, I've read some pages in Nielsens "Quantum Computing" book, it's very interesting, but especially at Grover's algorithm, there occurs a question for me. It is said that a phase shift is performed, which is defined as follows: ##|0\rangle \rightarrow |0\rangle \\ |x\rangle...
  23. L

    MATLAB Can I know the reconstruction of phase shift interferometry in Matlab

    I want to know the reconstruction of phase shift interferometry by angular spectrum method in matlab
  24. B

    Phase shift and circular polarization

    What is the phase difference between the right circularly polarized and left circularly polarized light of the same amplitude? And how do you calculate it?
  25. entropy1

    I Frequency spectrum of phase shift

    What does a 180 degree phase shift of a sinusoidal in a signal do to the frequency spectrum of the signal?
  26. opus

    Finding amplitude, period, phase shift on uglier functions

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  27. isukatphysics69

    Phase Shift in Sinusoidal Functions: Solving for Φ in Different Cases

    Homework Statement Homework Equations Asin(wt + Φ) The Attempt at a Solution let t = 0 Case A: -.10 = .20sin(Φ) sin-1(-.10/.20) = Φ = -0.52 Case B: .10 = .10sin(Φ) sin-1(.10/.10) = Φ = 1.57Case C: -.05 = .05sin(Φ) sin-1(-.05/.05) = Φ = -1.57Case D: 0 = .20sin(Φ) sin-1(0/.20) = Φ = 0 Now...
  28. J

    Question regarding filters

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  29. C

    I How does the thickness of a beam splitter affect the phase shift produced?

    I'm having trouble understanding the phase shift produced by a beam splitter. I seem to be finding conflicting information. I'm specifically looking to understand a 50/50 beam splitter where one side has a dielectric mirror, as shown in this figure from wikipedia: I understand the pi...
  30. M

    Question regarding phase shift between two signals

    Homework Statement Two sinusoidal voltages with amplitude 15Volts and frequency 2,771Hz are separated in time by 68% of a period. What is the phase shift in degrees between the two signals?Homework Equations y= Asin(omega)(x-h) The Attempt at a Solution I know my A is 15 and I'm pretty sure...
  31. Q

    Phase shift measurement using phase modulated signal

    Hello everyone, I'm actually working on developping a phase shift sensor using one phase modulated signal, i know that the title is confusing beaucause the phase shift measurement need two signals , I'm trying to do this with the zero crossing method so if I could found the timestamps of the...
  32. A

    How do I find the amplitude of the combined signal?

    Homework Statement Homework Equations Δφ = 2π (Δr/λ) The Attempt at a Solution I understand how to get the phase difference, but is the equation for the combined wave (second last line) just something I should memorize? Also, where does the sin term go in the last line? And why are the...
  33. C

    Phase shift of e.m. wave through a glass plate

    Homework Statement Consider a glass plate of refraction index n and thickness ## \Delta x ## placed between a point monochromatic source S and an observer O, as in picture. (a) Prove that, if absorption from the plate is neglegible, then the effect on the wave received by O is the add of a...
  34. Const@ntine

    Phase Shift of two sinusoidal waves

    Homework Statement Two sinusoidal waves in a string are defined by the wave functions y1 = 2.00 sin (20.0x – 32.0t) y2 = 2.00 sin (25.0x – 40.0t) where x, y1, and y2 are in centimeters and t is in seconds. (a) What is the phase differencebetween these two waves at the point x = 5.00 cm at t...
  35. V

    I Derivation of phase change parameter in dispersive medium

    Hi, I'm trying to evaluate the derivates of first, second and third order of the phase change parameter in a dispersive medium. In such medium the refractive index is a function of the wavelength. In my case it depends on the wavelength in vacuum. \begin{equation*} n(\lambda_0 )\end{equation*}...
  36. D

    Find effective value and phase shift for the current I

    Hi guys! I am wondering if someone can help me with an assigment i got, i would appreciate if someone could help me with it. Find effective value and phase shift for the current I in the link the tip is to use the superposition theorem http://imagizer.imageshack.us/a/img924/3673/R5qIAN.png
  37. U

    Understanding phase shift w/ time of 2 different frequencies

    Hi all, I hope this question is of an acceptable format to ask about here. I'm just having trouble trying to get a conceptual understanding of the following. I've been told that if I'm given two different frequencies that are completely in phase at time equal to zero, then I can find their...
  38. teetar

    Determining phase shift of two frequencies

    Homework Statement I'm given two frequencies: 4,000 Hz, and 5,000 Hz. They are completely in-shift at time ##t=0##. I am to find the time it takes them to get completely out of phase. Homework Equations The Attempt at a Solution I've not gotten waves very well thus far in physics. My teacher...
  39. T

    Phase Shift Oscillator

    1. The problem FIGURE 4(a) shows the circuit of an oscillator and FIGURE 4(b) gives the gain and phase response of the op-amp used. When the circuit was simulated in PSpice using an ideal op-amp, the circuit oscillated at the designed frequency. However when the ideal opamp was replaced by the...
  40. kostoglotov

    Will an infinite impedance cause no phase shift?

    Homework Statement imgur link: http://i.imgur.com/0Zc8nQe.png Homework Equations Y-Delta transformations The Attempt at a Solution Since it's a proof, I can't check the answer in the back. What I did: I transformed the three impedances in their delta config to a Y config, and my TI89...
  41. K

    Zero phase shift Op-Amp bandpass filter design

    Homework Statement "design a band pass circuit having a midband gain of 20 dB with -3 dB frequencies at 20 Hz and 20 KHz the amplifier should not produce any phase shift." does midband gain strictly apply to voltage gain (because that's how i look at it)? I was going to use a common collector...
  42. gsmtiger18

    Phase shift of light incident on 2 slits

    Homework Statement Light of wavelength λ = 450 nm is incident upon two thin slits that are separated by a distance d = 25 μm. The light hits a screen L = 2.5 m from the screen. It is observed that at a point y = 2.8 mm from the central maximum the intensity of the light is I = 55 W/m2. a)...
  43. J

    Value of a wave at a time with a phase shift.

    Homework Statement Calculate the value of the wave at t = (2, 3, 4, 10) ns 0.4 cos(10^8 * t + (1/3) * y) az Homework Equations N/A The Attempt at a Solution This is the last part of a problem. I have already found the phase shift of 1/3 and wavelength of 6 pi. I have already been given the...
  44. K

    Can I Create a 15 Degree Phase Shift with Transformers?

    I was wondering how I can get a 15 degree phase shift with transformers. I know a delta wye transformer creates a 30 degree phase shift.
  45. vetgirl1990

    Phase difference between waves in two-slit model

    Homework Statement In a double slit experiment, the distance between the slits is 0.2mm and the distance to the screen is 150cm. What is the phase difference in degrees, between the waves from the two slits arriving at point P, when the angular distance of P is 10 degrees relative to the...
  46. brainbaby

    Phase shift issue in Dominant Pole Compensation strategy....

    Hello guys please help me on this... The next hurdle in my understanding of frequency compensation comes as following… As the text says… My problem is that as we move from point 1 to 2, the frequency increases so the phase shift should also increase..(as phase shift depends on frequency)…...
  47. S

    Engineering Phase shift oscillator and circuit

    Homework Statement Gain & phase response of TL072 op-amp Homework Equations 'Frequency of oscillation was observed to be about 15 % lower'[/B] Why ? The Attempt at a Solution so at this frequency the op-amp has 45 phase shift, but why will this impact the oscillator and lower the...
  48. karush

    MHB N27.09 Derivative of tan and phase shift

    Find the function with the given derivative whose graph passes through point P. $$r'\left(\theta\right) =6+\sec^2 \left({\theta}\right), P\left(\frac{\pi}{4},0\right)$$ 6+sec^2(x) The phase shift appears to be 1 but not sure how to get that How do add another equation to desmos?
  49. Vannay

    EM wave reflection: phase shift off of conductor

    I know there is a pi phase shift when going from an area of lower index of refraction to higher. Is this phase shift still pi when going from a non-conducting dielectric with index of refraction n and reflection off a "good" conductor?
  50. Rectifier

    Delaying a signal 180 or 90 degrees

    Hey! How can I delay a sinusodial signal (voltage) 90 or 180 degrees? I have been thinking of a capacitor or an inductor in parallel with the voltage source but these components do not impact the phaseshift of the voltage but the current. Can anyone help me please? EDIT: I know that there are...