Specify wavelength inside rectangular waveguide

[ktx2222]

Hi all,

I have designed a rectangular waveguide. Frequency analysis is 1 GHz. The waveguide is filled by air and have the length is 3 times of wavelength in free space (900 mm). I simulated by HFSS and I got the E field likes the following photo:



It seems that the waveguide's length is just 2 times of wavelength in free space? I was confused. Please explain to me. Thank a lot!

 

[volker@muehlhaus]

See page 6
https://my.ece.msstate.edu/faculty/donohoe/ece3323waveguides.pdf

 

[FvM]

Each mode in a waveguide has a specific wavelength which is larger than the free space wavelength. Review the derivationtion in your favorite RF engineering text book.