Richard Clark, KB7QHC wrote:
"Who. in your estimation, does qualify to discuss it?"

If it`s about antennas, I nominate Kraus. If it`s about mathematics,
many marhematicians qualify.

In algebra, y = mx + b, (the point slope formula), is called linear
because it is the graph of a straight line.

In the discussion of transmission lines and antennas, you must admit
that a uniform transmission line enforces a unique characteristic
impedance (a resistance) on energy traveling in either direction. A
resistance is linear because Ohm`s law prevails. In free-space, everyone
agrees the characteristic impedance is about 377 ohms (a resistance).

Kraus says on page 2 of his 1950 edition of "Antennas":
"Let the transmission line now be connected to a dipole antenna as in
Fig.1-2. The dipole acts as an antenna because it launches a free-space
wave. However, it may also be regarded as a section of transmission line
(see Sec. 1-2). In addition, it exhibits many of the characteristics of
a resonator, since energy reflected from the ends of the dipole gives
rise to a standing wave on the antenna. Thus a single device, in this
case the dipole, exhibits simutaneously properties characteristic of an
antenna, transmission line, and a resonator.

Best regards, Richard Harrison, KB5WZI