Rf engineer
Member level 5
hi,
i have simulated a standard air filled Ku band rectangular waveguide with dimensions (15.8 x 7.9)mm for the dominant mode.
It has a cutt off at 9.49 GHz, and I am operatnig it between 12.4 - 18 GHz as per standard specifications.
It should give about 0dB S11 at cutt-off, but it gives -40dB or even less.
Furthermore when I vary the length of the guide along the propagation direction, I get the same S11 curve but shifted higher up in level.
Say the curve was below -80dB when the length was 2*lamda, and it shifts up to -40dB when the lenght is changed to 1*lamda.....
Why is this so. they should remain the same.
Please assist.
Best regards
i have simulated a standard air filled Ku band rectangular waveguide with dimensions (15.8 x 7.9)mm for the dominant mode.
It has a cutt off at 9.49 GHz, and I am operatnig it between 12.4 - 18 GHz as per standard specifications.
It should give about 0dB S11 at cutt-off, but it gives -40dB or even less.
Furthermore when I vary the length of the guide along the propagation direction, I get the same S11 curve but shifted higher up in level.
Say the curve was below -80dB when the length was 2*lamda, and it shifts up to -40dB when the lenght is changed to 1*lamda.....
Why is this so. they should remain the same.
Please assist.
Best regards
