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Radiated power of an electric dipole in free space

Posted Dec 10, 2021, 11:06 a.m. EST MEMS & Nanotechnology, RF & Microwave Engineering, Wave Optics 2 Replies

Nikolaos Kyvelos
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I am working on a simulation of an electic dipole(point source) with dipole moment of 1 Am, which oscillates harmonically with a frequency of 8,444910^14 Hz in free space. I am interested in evaluating the Green tensor in a 3D model. However, during the simulation the emitted radiated power is in the power 10^(15) W instead of 10^(46) W which is the correct result according to the bibliography. Has anybody encountered a similar problem while simulating electric dipoles behaving like a point source?

Thank you.

2 Replies Last Post Dec 13, 2021, 8:33 a.m. EST
Robert Koslover Certified Consultant
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Posted: 2 years ago Dec 11, 2021, 7:02 p.m. EST
Updated: 2 years ago Dec 11, 2021, 8:03 p.m. EST

You probably either did your arithmetic incorrectly or used the wrong equation. (After all, 10^46 W is greater than the power output of a supernova.) Regardless, you'll be happy to learn that your simulation gave the correct result to within 1%. Among others, you could take a look at page 16, equation 1-74, in Antenna Theory and Design by W.L. Stutzman and G.A. Thiele, published by John Wiley & Sons, 1981. The equation there will yield P = 10^15 W if using your numbers.

p.s. A static electric dipole moment, p, has units of charge x distance. The dipole moment that you refer to is in terms of current x distance. This is not the same thing, of course. Confusing the two leads to the error you reported.

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Scientific Applications & Research Associates (SARA) Inc.
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You probably either did your arithmetic incorrectly or used the wrong equation. (After all, 10^46 W is greater than the power output of a supernova.) Regardless, you'll be happy to learn that your simulation gave the correct result to within 1%. Among others, you could take a look at page 16, equation 1-74, in *Antenna Theory and Design* by W.L. Stutzman and G.A. Thiele, published by John Wiley & Sons, 1981. The equation there will yield P = 10^15 W if using your numbers. p.s. A static electric dipole moment, *p*, has units of *charge* x distance. The dipole moment that you refer to is in terms of *current* x distance. This is not the same thing, of course. Confusing the two leads to the error you reported.
Nikolaos Kyvelos
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Posted: 2 years ago Dec 13, 2021, 8:33 a.m. EST

Thanks a lot for your help!

Thanks a lot for your help!

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