Sometimes I really have to wonder who is at the helm of the USPTO. Claim 1 is an overly broad description of an antenna assembly that has been with us for many decades. The other claims may also be overly broad, but my jaw dropped on #1 so that's the focus here.

I'll be digging for reference material, but I figured I would put this out here to organize the findings of others.

Does anyone have a textbook showing a crossed dipole antenna using coax as the phasing mechanism whereupon the crossed dipoles are arranged over a ground plane?

I note the word "microwave" is in claim 1, but that merely suggests the frequencies are high and wavelengths short and is only a matter of scaling Prior Art to the new frequency... Obvious to any practitioner of the art.

1 Answer 1


I found this inside the textbook Modern Antenna Design, Thomas A. Milligan John Wiley & Sons, Jul 8, 2005 - Technology & Engineering - 580 pages. I do not know enough about RF and antennas to know if this is missing a key element. The U-shaped coax?

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  • 1
    This is spot on George. The U shaped coax is a delay line of 1/4 wave in length between the fed dipole and the remaining dipole to facilitate the 90 degree quadrature feeding of the two dipole elements over a ground plane. I read my copy of the book and it's quite clear this describes everything in claim 1, albeit wording scattered around the paragraphs, with the exception of "Microwave." Microwave to me is simply a scalar word. "Small" would be a suitable replacement. This technique is older than I am for sure.
    – JSH
    Jan 7, 2014 at 23:12
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    great, I wasn't sure - I transferred from the "real" EE program at MIT to the CS EE program as soon as we got to antennas.
    – George White
    Jan 7, 2014 at 23:53

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