Home |
Search |
Today's Posts |
|
#1
|
|||
|
|||
zaashy wrote:
"Matt" wrote in message ... How do you figure the speed in waveguide rather then free space? It is in several books, called lambda sub-g you could probably google it, starting with waveguide transmission. I can't remember, but I think is is about 75 to 85% It is determined by the dimentions of the waveguide, (same with coax, and material slows it down further) lambda is wavelength in free space. The phase velocity in a hollow, air filled waveguide is always faster than the speed of light, so the velocity factor is always 100%. The amount faster depends on the operating frequency relative to the waveguide's cutoff frequency. The velocity factor in a hollow, air-filled guide = 1 / sqrt(1 - (fc/f)^2) where fc = cutoff frequency f = operating frequency Too bad you can't get information through a waveguide that fast. It goes at the group velocity, which of course is always slower than the speed of light. Sigh. Roy Lewallen, W7EL |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Inverted ground plane antenna: compared with normal GP and low dipole. | Antenna | |||
The "TRICK" to TV 'type' Coax Cable [Shielded] SWL Loop Antennas {RHF} | Antenna | |||
Mobile Ant L match ? | Antenna | |||
Poor quality low + High TV channels? How much dB in Preamp? | Antenna |