en>Ph.D. Chemical Engineering |
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| {{About|side lobes in antenna engineering|side lobes in digital signal processing|spectral leakage}}
| | It's going to suddenly make your ex boyfriend want you back. Play hard to get (don't over do it) and let her make the first move, and you will come out on top. Just keep doing these things and you will when them back. t a rational thing and the better solution to getting your ex back is to cut off all communication for a while. What I mean is you need to transform yourself into the kind of person that your ex would love to be with; someone that they find is extremely hard to stay away from. <br><br>Although you can not go back into the past, and you can not change what happened, learn from the mistakes that were made and you can try to learn and grow from experiences. People are generally not attracted to negative, miserable people. Amazingly, there are ways , which you can win back the love of your life. But it may not be possible to stay away from him if he is a co-worker or a class mate and you have to be together often. Girls see this good quality of being faithful to one particular yet another as a big turn on. <br><br>For now, just keep advancing until you get a front row seat for an execution. These people end up getting back together and giving things another shot, because they loved and missed each other - and the times they shared. And until you come to that realization, any and all attempts to contact your boyfriend will backfire and be met with resistance, not open arms. You are drunk dialing or sending thousands of text messages to your ex. In time, he will come to realize what he's lost in you, and this will work out well in your efforts to get him back. <br><br>As an example, you can look at joining the neighborhood gym to become a lot more fitter and stronger or you might even elect to get involved with active community service. A man will be trapped inside a room filling with gas, and he'll beg for you to save him. s just a matter of having the right combination of you working and him not resisting. Focus on yourself and your own happiness rather than seeking out a new relationship. You have to remember that you are no longer a couple. <br><br>If your ex girlfriend enjoys bringing up things that you two used to do or if she seems focused on when you two were happy and in love, that's an indicator that she wants to rekindle that part of your relationship. While you participate in most of these activities, you will be amazed that before you know it you'd have become a much more confident and improved individual altogether. If the relationship overall was a good one, with the normal ups and downs of life, a balance of good and bad times and a basic love and respect for one another , then the following should help you and your ex get back together. So when you are apart, don’t forget to rebuild your image back up and make something worthwhile of yourself. Now it is time for you to take control and turn the situation around.<br><br>In the event you liked this information in addition to you desire to obtain more info relating to [http://www.kok1235.info/ how to tell your ex you want him back] kindly go to our own internet site. |
| {{unreferenced|date=April 2008}}
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| [[File:Sidelobes en.svg|thumb|A typical [[directional antenna]] radiation pattern in [[polar coordinate system]] representation, showing side lobes. The radial distance from the center represents signal strength.]]
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| [[File:Typical Antenna Pattern.jpg|thumb|250px|A typical antenna radiation pattern in [[cartesian coordinate system]] representation showing side lobes.]]
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| {{Antennas|Radiation sources and regions}}
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| In [[Antenna (radio)|antenna]] engineering, '''side lobes''' or '''sidelobes''' are the lobes (local maxima) of the [[Near and far field|far field]] [[radiation pattern]] that are not the [[main lobe]].
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| The radiation pattern of most antennas shows a pattern of "''lobes''" at various angles, directions where the radiated signal strength reaches a maximum, separated by "''[[null (radio)|null]]s''", angles at which the radiated signal strength falls to zero. In a [[directional antenna]] in which the objective is to emit the radio waves in one direction, the lobe in that direction has a larger field strength than the others; this is the "''[[main lobe]]''". The other lobes are called "''side lobes''", and usually represent unwanted radiation in undesired directions. The '''side lobe''' in the opposite direction (180°) from the main lobe is called the "''back lobe''". In [[Transmitter|transmitting]] antennas, excessive side lobe radiation wastes energy and may cause [[Electromagnetic interference|interference]] to other equipment. Classified information may be picked up by unintended receivers. In [[Radio receiver|receiving]] antennas, side lobes may pick up interfering signals, and increase the noise level in the receiver.
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| The power density in the side lobes is generally much less than that in the main beam. It is generally desirable to minimize the sidelobe level (SLL), which is measured in [[decibel]]s relative to the peak of the main beam. The main lobe and side lobes occur for both conditions of transmit, and for receive. The concepts of main and side lobes, radiation pattern, aperture shapes, and aperture weighting, apply to [[optics]] (another branch of electromagnetics) and in [[acoustics]] fields such as [[loudspeaker]] and [[sonar]] design, as well as antenna design.
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| For a rectangular aperture antenna having a uniform amplitude distribution (or uniform weighting), the first sidelobe is -13.26 dB relative to the peak of the main beam because for such antennas the radiation pattern has a [[canonical form]] of
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| <center> | |
| <math> | |
| \displaystyle\mbox{Radiation Pattern (in units of dB)} \propto 20\log_{10}\left(\left|\frac{\sin(X)}{X}\right|\right)
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| </math>
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| </center>
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| Simple substitutions of various values of <math>\displaystyle X</math> into the canonical equation yield the following results:
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| <center>
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| {| class="wikitable"
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| |-
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| ! <math>\displaystyle X</math>
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| ! Radiation Pattern
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| ! Explanation
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| |-
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| | <math>\displaystyle 0</math>
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| |align=right| <math>\displaystyle0~\mbox{dB}</math>
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| | peak of main beam
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| |-
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| | <math>\displaystyle 3.14=\pi</math>
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| |align=right| <math>-\infty~\mbox{dB}</math>
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| | first null
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| |-
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| | <math>4.49\approx\frac{3\pi}{2}</math>
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| |align=right| <math>\displaystyle-13.26~\mbox{dB}</math>
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| | peak of first sidelobe
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| |-
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| | <math>\displaystyle 6.28=2\pi</math>
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| |align=right| <math>-\infty~\mbox{dB}</math>
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| | second null
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| |-
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| | <math>7.72\approx\frac{5\pi}{2}</math>
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| |align=right| <math>\displaystyle-17.83~\mbox{dB}</math>
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| | peak of second sidelobe
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| |}
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| </center>
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| For a circular aperture antenna, also having a uniform amplitude distribution, the first sidelobe level is -17.57 dB relative to the peak of the main beam because in this case, the radiation pattern has a [[canonical form]] of
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| <center>
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| <math>
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| \displaystyle\mbox{Radiation Pattern (in units of dB)} \propto 10\log_{10}\left(\left|2\frac{J_1(X)}{X}\right|^2\right)
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| </math> | |
| </center> | |
| where <math>\displaystyle J_1(x)</math> is the [[Bessel function of the first kind]] of order 1. Simple substitutions of various values of <math>\displaystyle X</math> into the canonical equation yield the following results:
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| <center>
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| {| class="wikitable"
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| |-
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| ! <math>\displaystyle X</math>
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| ! Radiation Pattern
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| ! Explanation
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| |-
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| | <math>\displaystyle 0</math>
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| |align=right| <math>\displaystyle0~\mbox{dB}</math>
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| | peak of main beam
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| |-
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| | <math>\displaystyle 3.83</math>
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| |align=right| <math>-\infty~\mbox{dB}</math>
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| | first null
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| |-
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| | <math>\displaystyle5.14</math>
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| |align=right| <math>\displaystyle-17.57~\mbox{dB}</math>
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| | peak of first sidelobe
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| |-
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| | <math>\displaystyle7.02</math>
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| |align=right| <math>-\infty~\mbox{dB}</math>
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| | second null
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| |-
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| | <math>\displaystyle8.42</math>
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| |align=right| <math>\displaystyle-23.81~\mbox{dB}</math>
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| | peak of second sidelobe
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| |}
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| </center>
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| A uniform aperture distribution, as provided in the two examples above, gives the maximum possible [[directivity]] for a given aperture size, but it also produces the maximum side lobe level. Side lobe levels can be reduced by tapering the edges of the aperture distribution (changing from uniformity) at the expense of reduced [[directivity]].
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| The nulls between sidelobes occur when the radiation patterns passes through the origin in the [[complex plane]]. Hence, adjacent sidelobes are generally 180° out of phase to each other.
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| Because an antenna's [[far field]] [[radiation pattern]] is a [[Fourier Transform]] of its aperture distribution, most antennas will generally have sidelobes, unless the aperture distribution is a [[Normal distribution|Gaussian]], or if the antenna is so small, as to have no sidelobes in the visible space. Larger antennas have narrower main beams, as well as narrower sidelobes. Hence, larger antennas have more sidelobes in the visible space (as the antenna size is increased, sidelobes move from the [[Evanescent wave|evanescent space]] to the [[visible space]]).
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| [[File:Typical antenna pattern with grating lobes.jpg|thumb|250px|A typical [[radiation pattern]] of [[phased array]]s whose inter-element spacing is greater than half a wavelength, hence the radiation pattern has grating lobes.]]
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| For discrete aperture antennas (such as [[phased array]]s) in which the element spacing is greater than a half wavelength, the spatial [[aliasing]] effect causes some sidelobes to become substantially larger in amplitude, and approaching the level of the main lobe; these are called [[grating lobe]]s, and they are identical, or nearly identical in the example shown, copies of the main beams. 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 other side lobes. The mathematics of grating lobes is the same as of [[X-ray diffraction]].
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| == External links ==
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| *[http://www.antenna-theory.com/basics/radPatDefs.php Sidelobes and Beamwidths - An Antenna Tutorial]
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| [[Category:Antennas]]
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| [[Category:Radio frequency propagation]]
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| [[de:Antennendiagramm#Elemente eines Antennendiagramms]]
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It's going to suddenly make your ex boyfriend want you back. Play hard to get (don't over do it) and let her make the first move, and you will come out on top. Just keep doing these things and you will when them back. t a rational thing and the better solution to getting your ex back is to cut off all communication for a while. What I mean is you need to transform yourself into the kind of person that your ex would love to be with; someone that they find is extremely hard to stay away from.
Although you can not go back into the past, and you can not change what happened, learn from the mistakes that were made and you can try to learn and grow from experiences. People are generally not attracted to negative, miserable people. Amazingly, there are ways , which you can win back the love of your life. But it may not be possible to stay away from him if he is a co-worker or a class mate and you have to be together often. Girls see this good quality of being faithful to one particular yet another as a big turn on.
For now, just keep advancing until you get a front row seat for an execution. These people end up getting back together and giving things another shot, because they loved and missed each other - and the times they shared. And until you come to that realization, any and all attempts to contact your boyfriend will backfire and be met with resistance, not open arms. You are drunk dialing or sending thousands of text messages to your ex. In time, he will come to realize what he's lost in you, and this will work out well in your efforts to get him back.
As an example, you can look at joining the neighborhood gym to become a lot more fitter and stronger or you might even elect to get involved with active community service. A man will be trapped inside a room filling with gas, and he'll beg for you to save him. s just a matter of having the right combination of you working and him not resisting. Focus on yourself and your own happiness rather than seeking out a new relationship. You have to remember that you are no longer a couple.
If your ex girlfriend enjoys bringing up things that you two used to do or if she seems focused on when you two were happy and in love, that's an indicator that she wants to rekindle that part of your relationship. While you participate in most of these activities, you will be amazed that before you know it you'd have become a much more confident and improved individual altogether. If the relationship overall was a good one, with the normal ups and downs of life, a balance of good and bad times and a basic love and respect for one another , then the following should help you and your ex get back together. So when you are apart, don’t forget to rebuild your image back up and make something worthwhile of yourself. Now it is time for you to take control and turn the situation around.
In the event you liked this information in addition to you desire to obtain more info relating to how to tell your ex you want him back kindly go to our own internet site.