I'm currently reading "Reflections: Transmission Lines and Antennas" by M. Walter Maxwell, W2DU. This book explains well why the energy is not lost because of high SWR during transmitting, assuming the feedline and ATU are lossless. It also provides plots that allow determining the actual loss when the feedline has losses.
- What happens in a low loss feed-line with a high SWR
- What is the actual loss in a feed line with high SWR?
- (When) does a transceiver re-reflect 100% of reflected power?
- http://www.arrl.org/files/file/Technology/tis/info/pdf/q1106037.pdf (see Fig 1)
What I don't quite understand though is what happens to the received signal level in the high SWR case.
Let's say the antenna impedance on a given frequency is 100 Ohm, the feedline is lossless 50 Ohm, the transceiver input impedance is 50 Ohm. Between the antenna feed point and the feedline SWR = 2, 11% reflected power. Case a) there is no ATU. Case b) there is a lossless LC-match between the transceiver and the feedline that matches seen impedance to 50 Ohm. How much of the received power will be delivered to the transciever in cases a) and b)?