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  1. #1
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    In which application can I use an antenna with such a gain plot?

    The gain plot is attached. It is a microstrip patch antenna. It has a wide impedance bandwidth between 2 and 5 GHz but its gain at broadside is negative very much throughout the bandwidth. I believe the low gain may be due to substrate edge diffraction.

    In which application can I use an antenna with such a gain plot?

    Click image for larger version. 

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  2. #2
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    Re: In which application can I use an antenna with such a gain plot?

    I dont believe a microstrip patch antenna will have such a wide impedence bandwidth. Normally they only give less than 5% bandwidth. The gain plot seems to back this up, but doesnt say if it is peak gain or not.



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    Re: In which application can I use an antenna with such a gain plot?

    It is peak gain. Could you tell me if it is useful for any application regardless if it is microstrip or not? Thanks



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    Re: In which application can I use an antenna with such a gain plot?

    Thats a very broad question. Amd hence the broad answer is yes you could use it for lots of applications. But, i guess you want a specific answer such as this amtenna would be good for application X.

    So lets take a look, the peak gain appears to be about 4dBi at around 1.9ghz. For frequencies above that the gain looks pretty poor. If your application was higher frequency than that you could build a better(and smaller antenna). So is the question what is a good application for an 1.9ghz patch antenna?



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    Re: In which application can I use an antenna with such a gain plot?

    can it be good for say a PIFA like application....since PIFA has usually negative gain?

    what is the difference between peak and realized gain?



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  6. #6
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    Re: In which application can I use an antenna with such a gain plot?

    PIFA is a type of antenna, not an application. Normally we start with an application and work out what sort of properties we need for our antenna. Then we select(or develop) an antenna to suit. To do it the other way round is a bit odd. Can you explain any background about what you are trying to achieve?

    Peak gain is the maximum in some dimension. In the case of my question i was refering the the peak value over all azimuth and elevation angles. It could however mean the peak across a range of frequencies, but that wouldn't make much sense in this context.

    Realized gain is the gain including all losses (missmatch and ohmic) normally when connected to a 50ohm system. This is normally the figure i would expect to be quoted with an antenna for sale.

    You can have a peak realised gain or a peak directivity.



  7. #7
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    Re: In which application can I use an antenna with such a gain plot?

    in this case, my plot was the realized gain.



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