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A typical radiation pattern of phased arrays whose inter-element spacing is greater than half a wavelength, hence the radiation pattern has grating lobes.. For discrete aperture antennas (such as phased arrays) in which the element spacing is greater than a half wavelength, a spatial aliasing effect allows plane waves incident to the array from visible angles other than the desired direction ...
Grating lobes are a special case of a sidelobe. In such a case, the sidelobes should be considered all the lobes lying between the main lobe and the first grating lobe, or between grating lobes. It is conceptually useful to distinguish between sidelobes and grating lobes because grating lobes have larger amplitudes than most, if not all, of the ...
These equations can be solved to predict the nulls, main lobe, and grating lobes of the array. Referring to the exponents in the array factor equation, we can say that major and grating lobes will occur at integer , =,,, … solutions to the following equations: [4] [41] [page needed]
Now, suppose that the excitation coefficients are positive real variables. In this case, always in the domain of , the array factor magnitude has a main lobe with maximum value at =, called mainlobe, several secondary lobes lower than the mainlobe, called sidelobes and mainlobe replicas called grating-lobes. Grating lobes are a source of ...
Since side lobes of the Airy disk are responsible for degrading the image, techniques for suppressing them are utilized. If the imaging beam has Gaussian distribution, when the truncation ratio (the ratio of the diameter of the Gaussian beam to the diameter of the truncating aperture) is set to 1, the side-lobes become negligible and the beam ...
The extra bandwidth comes from the controlled taper and large termination radius of the cone. The cone shape and flat disk disperse the local electric field. This reduces stored energy in the electric field, reducing antenna Q while also reducing losses. The elevation pattern might be distorted with grating lobes.
As of Jan. 15, Ninja claims he now has a low taper fade — but whether the haircut is an accurate low taper fade seems to be up for debate in the comments.
In addition, it is found that the value of β changes very little as the stub is moved, and α varies over a very large range. This feature allows to taper the antenna aperture to control sidelobes. The fact that the L-shaped structure strongly leaks may also be related to another leakage mechanism: the use of leaky higher modes.