any one please have an idea (x band waveguide )

an empty x band (8.2_12.4) rectanglur waveguide with dimensions of 2.286 cm by 1.016cm is to be connected to an x band waveguide of the same dimsions but filled with εr=2.56 .to avoide reflection an x band waveguide of the same dimsions quarter wavelenght long section is inserted between the two assumedominate mode at 10 ghz

how to find the impedance of the quatre-wave lengh section wave guide

Well, it is pretty straightforward.

In the air guide, there is a wave impedance (Zinput=E/H). In the dielectric guide there is a lower wave impedance (Zoutput=E2/H2). You want to design the quaterwave section in between those two to be Zmiddle=√(Z2*Z0).

Off of the top of my head I do not recall the formula for wave impedance in the guides, but it is easily looked up.


If this were in free space, it would be easy. The impedance is simply η=√(μ/ε) in free space, so the impedance of the loaded section is probably (just guessing now) Zunloaded*1/√2.56.

thanx alot for your help