Home |
Search |
Today's Posts |
#18
|
|||
|
|||
Matt wrote:
Can I make a slot antenna out of round pipe rather then rectangular? I assume you are referring to a circular waveguide with slot radiators cut into the surface. The usual arrangement is to use a rectangular waveguide with dimensions chosen so that only one possible propagation mode exists for the wavelength in use. This makes it fairly simple to determine suitable locations and dimensions of the radiating slots for the desired current distribution. The problem with circular waveguide is that it does not constrain the polarization to any particular orientation. Even if the wave is launched in a known orientation, the presence of the slots may very well induce a 'twist' in the propagating wave which will affect the excitation of the slots in a way which may be extremely difficult to predict, or even measure. One remedy is to insert features inside the circular waveguide which constrain the propagating wave to the desired polarization direction. Specific methods can be found in the microwave literature but I think you will find fabrication of rectangular waveguide by far the easiest solution if you're only going to construct a few units. bart wb6hqk I am having a hard time finding inexpensive rectangular tubing for working in 33cm band. Figure I need 2" x 8" and its not cheap. I can get 7" pipe much cheaper. Matt |
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 |