Regarding RF Module

Hi,
Problem: Interaction of structures with cylindrical EM wave.
My question is "How can we excite a cylindrical EM wave in 'Electromagnetic Waves' node of RF module?". Plane wave can easily be defined by putting an expression 'E0*exp(-j*emw.k0*z)' for a wave propagating in the z-direction with amplitude E0. But I am not able to find a way to excite cylindrical wave in COMSOL.
Can anyone enlighten me with his/her expertise or knowledge.
Thanks in advance. Looking forward for your answers.

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Mahesh Singh Bisht