Feeding in waveguide?

Hi,

Is there any specific formula or method as to what should be the length of probe that is to be inserted in the waveguide for feeding purpose. There are so many combinations that can take place but is there any specific type of feeding for specific purpose or just hit and trial method technique.

Hi,
Printed Qusi-Yagi antenna can feed a waveguide efficirntly with 50% bandwidth.

depending which mode you want stimulus in the waveguide,it exist several probe feeding mode can be classify in two type :current(magnetic) stimulus and voltage(electrical) stimulus. some addition waveguide circuit needed to make match and avoid higher order mode. Check microwave theory textbook will be helpful.

Hi
Use the moment methods,I think it's the best method to analyse the feeding in waveguide.