phase front मीनिंग इन हिंदी

उदाहरण वाक्य

1. In geometric optics, the eikonal equation describes the phase fronts of waves.
2. The two lenses act as a telescope producing a flat phase front of a Gaussian beam on a virtual end mirror.
3. A " pilot " microwave beam emitted from the center of the rectenna on the ground establishes a phase front at the transmitting antenna.
4. As the frequency is changed, the phase front across the aperture tends to tilt, with the result that the beam is moved in elevation.
5. There, circuits in each of the antenna's subarrays compare the pilot beam's phase front with an internal clock phase to control the phase of the outgoing signal.
6. Since not the phase itself, but the first derivative of the phase front is measured, ABI is less sensitive to low spatial frequencies than crystal interferometry but more sensitive than PBI.
7. The plane wave spectrum is a continuous spectrum of " uniform " plane waves, and there is one plane wave component in the spectrum for every tangent point on the far-field phase front.
8. The utility of the point source concept comes from the fact that a point source in the 2D object plane can only radiate a perfect uniform-amplitude, spherical wave  a wave having perfectly spherical, outward travelling phase fronts with uniform intensity everywhere on the spheres ( see Huygens Fresnel principle ).
9. In RF detection the antenna is rarely larger than the wavelength so all excited electrons move coherently within the antenna, whereas in optics the detector is usually much larger than the wavelength and thus can intercept a distorted phase front, resulting in destructive interference by out-of-phase photo-generated electrons within the detector.
10. However, since the standard deviation of the coherent sum of the speckles is exactly equal to the mean speckle intensity, optical heterodyne detection of scrambled phase fronts can never measure the absolute light level with an error bar less than the size of the signal itself . " This upper bound signal-to-noise ratio of unity is only for absolute magnitude measurement " : it can have signal-to-noise ratio better than unity for phase, frequency or time-varying relative-amplitude measurements in a stationary speckle field.