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Microstrip antenna array

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suyan

Newbie level 6
How to calculate elements spacing for antenna array:?:

The element spacing must be such that grating lobes will not occur. The formula can be found in any antenna books.

suyan said:
How to calculate elements spacing for antenna array:?:

Since individual microstrip antenna radiats very small in θ=90 degree plane, the effect of grating lobe for microstrip array will be smaller than that of most other type antenna arrays. In many cases spacing close to λ shows small effect of grating lobe, but first look at your requirements.

suyan

Points: 2
If the elements space is large more than one wavelength , it occurs grating lobe.

If the elements space is small , it may cause mutual coupling .

thanks for replying, i am really new in designing the antenna. the formula i already know. what u mean by grating lobes ? can anyone add me in msn? su_yan_e212@hotmail.com

Grating lobes are the side lobes with the same level of gain as the main lobe, which are not desired by the proposed antenna radiation pattern.

then u know when designing an antenna array, what is feed line width? and how to calculate effective dielectric constant for right and left side impedence? i am using the book: "CAD Microstrip Antenna for wirless applications" and i am using the window application to use it.

You have to define a lot of requirements before select the inter-elements spaicng, at least:

- peak gain
- beamwidth (in both planes)
- radiator element size and coupling
- bandwidth

the grating lobes are not a concern if you don't have to scan the beam away the boresight direction, unless you have an inter-element spacing > 0.9/1.0 Lambda.

Typically the useful range is between 0.6-0.75 Lambda.

But without the above listed information you question is not complete !

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