log periodic antenna calculator

I'm check this calculator and I can said that this simple calculation isn't correct or not agree with EM simulation and measurements.

Anyway, LPDA structure check firstrly in any wire based codes(MOM) and on the end in full 3D based. Impedance is very critical(wire method isn't correct) and because use full 3D simulator.

What I am getting is the longest element is just resonant at the low frequency end and the far end of the array is resonant way above the highest frequency. I have tried radically different frequency ranges and tau values

Hi flatulent

If you are looking for good LPDA calculator you can find
it in PCAAD Ver.5 and a lot of other good stuff see in

http://www.antennadesignassociates.com/pcaad5.htm

Read this book https://www.edaboard.com/viewtopic.p...highlight=lpda

AND

Use EZNEC, MMANA or SuperNEC (working with Matlab) to simulate it

Hello, abdoeng,

I'm trying to build in domestic conditions LPDA antenna like on the attached picture (Lectrosinics ALP500), but am having some difficulties with the measurements.

Also, I checked your excel formula, but it's designed for tube LPDA.

Could you, please, help me with correct sizes and proportions for this model?

Thanks in advance.

hello,
i'm triying to design log periodic antenna but i dont know how to start. below is the detail info:
frequency 1GHz ~ 6GHz.

can anybody can help me how to design and the calculation.

length of the largest dipole: L1=λmax/2 (λmax corresponding to fmin)
length of the smallest dipole: LN=λmin/2 (λmin corresponding to fmax)

geometric ratio: τ=L(n+1)/Ln
spacing factor: σ=dn/(2*Ln) , where dn is the spacing between dipole number n+1 and dipole number n .

Ln=L1*τ^(n-1)
dn=d1*τ^(n-1)

you can find these formulas in Balanis's Antenna book.