Cecil Moore wrote:

An RF standing wave does not behave like an EM wave
nor does it meet the definition of an EM wave which can be represented
by a Poynting vector. The Poynting vector for an RF standing wave has
a magnitude of zero and no direction.

So much for the Poynting vector of a position envelope. What are your
thoughts regarding the Poynting vector for a time varying envelope of
an electromagnetic wave? :-)

ac6xg