Nic. Santean wrote:
So, the problem is that the dipole generates two fields (E&M)
out of (time-)phase; whereas EM propagation in free space
implies two fields in phase. The "contradiction" can not be more
clear than this.

If the antenna is a traveling-wave antenna, the E-fields and H-fields will
be in time phase, physically orthogonal to each other's plane and orthogonal
to the direction of energy flow. Reference: "Antennas", Kraus & Marhefka,
third edition, sec. 6-8. "Since the current is entirely in the 'z' direction,
the magnetic field has but ONE component, H(epsilon)." The ratio of the E-
field to the H-field will be the characteristic impedance of the traveling-
wave antenna. Also: _Optics_, by Hecht, Section 3.2, Electromagnetic Waves.

For standing-wave antennas, like a dipole, there is MORE THAN ONE magnetic
field component.

For standing-wave antennas, like a dipole, there are forward-traveling
waves from the feedpoint to the ends of the antenna and reflected
traveling waves reflected back from the ends. This is similar to an un-
terminated transmission line. It is well known that the total net voltage
and total net current can be 90 degrees out of phase in a lossless un-
terminated transmission line. Approximately the same holds true for
standing-wave antennas. The total net voltage is the phasor sum of
the forward voltage and reflected voltage which relates to the total
E-field. The total net current is the phasor sum of the forward current
and reflected current which relates to the total H-field. And of
course, as in a transmission line, the total voltage and total current
can be almost 90 degrees out of phase at the two points equi-distant from
the feedpoint and the ends. So of course, the E-field and the H-field near
the antenna will possess the same phase as the total net voltage and total
net current flowing in the wire at the same orthogonal plane.
--
73, Cecil http://www.qsl.net/w5dxp



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