1. The problem statement, all variables and given/known data In a rectangular waveguide, b = a/2, find the section, if exists, in which the magnetic field is circularly polarized (TE10 mode). 2. Relevant equations Rectangular waveguide equations for TE10 mode (referencing Pozar book). Circular polarization (π/2 out of phase and same amplitude). 3. The attempt at a solution For TE10 mode: Hz, Ey and Hx are known, Ex = Ez = Hy = 0. For the magnetic field to be circularly polarized Hz and Hx must be π/2 out of phase so π/2 = tan-1(Hz/Hx), but I'm not sure about this since Hx is already multiplied by 'j'. Someone might help, please?