what is the requirements to have standing waves?

Question

ujjwal · Answer

Two waves with equal amplitude travelling in opposite direction... they superpose to give standing wave..

ujjwal · Answer

And waves should have same frequency!

anonymous · Answer

http://en.wikipedia.org/wiki/Standing_wave

mani_jha · Answer

Yeah, a boundary would satisfy all that. A 'wall' on both sides is required. When you pluck a guitar string, you produce waves that move in opposite directions(one towards your hand, and the other towards the body of the guitar), get reflected and then come together and superimpose to produce standing waves.

vincent-lyon.fr · Answer

@Mani_Jha 
Only 1 wall is required for standing waves.
2 walls will impose quantification of the possible frequencies, whereas with one wall, all frequencies are allowed.

anonymous · Answer

a origin point , same frequency , constant  air resistane

radar · Answer

A standing wave will exist if the load (antenna) does not equal to the characteristic impedance of the transmission line.  This voltage standing wave is referred to as
"VSWR"  (Voltage Stand Wave Ratio) and this is desirable to keep to a minimum (1:1)