# Which is the physical reason for why a dipole is an isotropic radiator?

Good morning. I was wondering which is the exact physical reason for why a dipole (e.g. a $$\lambda/2$$ dipole) has the equal radiation pattern in all directions. I have founded many formulas but I can't get the point in practice. Many thanks.

• Can you show us some of these formulas? A dipole is not an isotropic radiator. – garyp Jul 17 '19 at 10:23
• I mean, I know that a dipole (Hertzian dipole) has a very low directivity (0 at all) and if I need more of this parameter I should go for an array config. I am interested about the physical reason of this low directivity property. Many thanks. – muserock92 Jul 17 '19 at 10:26
• The directivity of a Hertzian dipole is not zero. It's 1.5-1.76 dBi. Granted, it's lower than basically any other configuration, but it's not zero, because, again, a dipole is not an isotropic radiator. – probably_someone Jul 17 '19 at 10:29
• Many thanks. Can you tell me why a dipole has such a low directivity value? I know the directivity depends on the ratio lenght versus $\lambda$, but can I read this by a physical reason? Many thanks again. – muserock92 Jul 17 '19 at 10:32