Just a nit: You said:

If there are reflections, the voltage
and current are in phase only every 1/4 wavelength.

Actually, if there are reflections, the voltage and current ar NEVER in
phase.

"Cecil Moore" wrote in message
...
palaniappan chellappan wrote:
Thanks for replies, but i couln't able to conclude anything from the
two complementary replies i got :-(.

If the voltage and current are in phase at every point up
and down a transmission line (with a resistive Z0), there
are no reflections. If there are reflections, the voltage
and current are in phase only every 1/4 wavelength.

Which book is best for learning about concepts like
antenna,reflection,swr, etc. I am working only at hf band. If there is
any online tutorial ?

Unfortunately, only the older (pre 1990's) ARRL Antenna
Books present a decent explanation of reflections. The ARRL
has stopped discussing forward and reflected waves and
started discussing impedance matching. IMO, it's part of
the dumbing down of the ARS along with the rest of the US.

Walter Maxwell literally wrote the book on "Reflections". His
web page is: http://www.w2du.com Worldradio magazine is on
the verge of publishing "Reflections III". Their web page
is: http://www.wr6wr.com

You might get something useful from my Worldradio magazine
article available at: http://www.qsl.net/w5dxp/energy.htm
--
73, Cecil http://www.qsl.net/w5dxp