Jim Kelley wrote:
Non-sequitur, ad absurdum, ad nausium.
I'm going to let you do the math to convince yourself
that Kraus is correct, given his assumptions about thin
wire antennas.
Assume two traveling-wave currents, each with a maximum
magnitude of 1.0 amps, and flowing in opposite directions.
They are a forward current wave and a reflected current wave,
If and Ir. This will set up a classical current standing wave.
Here are five possible superpositions of those two currents.
('+' is the 0,0 origin)
(1)*********************************************** **************
+------- 1.0 +-------
If = 1.0 at zero degrees Ir = 1.0 at zero degrees
What is the phase of the sum of those two phasors? __________
(2)*********************************************** **************
/ +
/ \
/ \
+ \
If = 1.0 at 45 degrees Ir = 1.0 at -45 degrees
What is the phase of the sum of those two phasors? __________
(3)*********************************************** **************
| +
| |
| |
| |
+ |
If = 1.0 at 90 degrees Ir = 1.0 at -90 degrees
What is the phase of the sum of those two phasors? __________
(4)*********************************************** **************
\ +
\ /
\ /
\ /
+ /
If = 1.0 at 135 degrees Ir = 1.0 at -135 degrees
What is the phase of the sum of those two phasors? __________
(5)*********************************************** **************
-------+ -------+
If = 1.0 at 180 degrees Ir = 1.0 at -180 degrees
What is the phase of the sum of those two phasors? ___________
************************************************** ************
When you guys figure it out, you will realize why Kraus shows only
two possible phases for current in standing wave antennas, zero
degrees and 180 degrees. Everyone who doubts the binary nature of
the phase of standing waves, please post your answers.
--
73, Cecil, W5DXP
|