Home |
Search |
Today's Posts |
#9
|
|||
|
|||
Dr. Slick wrote:
"I don`t have that book." I don`t have Kraus either and I miss it. Space has a magnetic permeability and a dielectric constant. The square root of their ratio is the characteristic resistance of space. It is 376.7 ohms = 120 pi ohms. The reciprocal of the square root of the product of the permeability and dielectric consrtant of space is the velocity of EM radiation propagation. It is 300 million m/sec. The above is courtesy of King, Mimno, and Wing, in "Transmission Lines, Antennas, and Wave Guides", on page 73. The authors must have considered the information important as they repeated it on page 117. They followed the repetition with a discussion of the radiation resistance and input resistance of an antenna. They note that radiation resistance can`t be measured between two terminals in a circuit. The I squared R of the antenna power does not conveniently compute as might be expected with circuit terminals, as current is a variable along an antenna in most cases. Best regards, Richard Harrison, KB5WZI |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Conservation of Energy | Antenna |