The effect of bound states in microwave waveguides on electromagnetic wave propagation

The transmission of a TE microwave field with a frequency ω through Λ, T, and X waveguide junctions filled with a ferromagnetic is considered. These junctions are known to have bound states with below-cutoff frequencies. A probing microwave radiation with a frequency Ω applied to the scattering region generates magnetic oscillations with frequencies ω+nΩ (where n=0, ±1, ±2, ...), which resonantly combine with the bound waveguide states. This effect provides for a new method of studying bound waveguide states and efficiently controlling the transmission of microwave radiation.