Cut and paste of my other post:
>First do the hand calculations for the patch antenna size, they can be found in many textbooks.
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>Next, simulate the antenna and see how close it matches your hand calculations.
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>I can recommend:
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>Microstrip Antenna Design Handbook by Bahl, Bhartia et al.
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>Good antenna theory textbooks are:
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>Antenna Theory and Design by Stutzman and Thiele
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>Antenna Theory: Analysis and Design by Balanis
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>Older editions can be found on AbeBooks and are just fine.
>
>Antenna-Theory.com is a good online antenna reference.
>
>Try posting in /r/rfelectronics for help later.
I linked directly to patch antenna calculations on the Antenna-Theory website.