Consider a ground plane that is covered with a type of Bakelite (assume dielectric constant 4.0). The thickness of the dielectric is 12.5 mm, as indicated in the figure below. a) Calculate the first two modes supported by this structure and identify the cutoff frequencies. b) For each mode identified in a), find the phase constant within the dielectric in the direction normal to the interface when the incident angle (defined via the normal to the interface - as shown below) is twice the critical angle.

Consider a ground plane that is covered with a type of Bakelite (assume dielectric constant 4.0). The thickness of the dielectric is 12.5 mm, as indicated in the figure below. a) Calculate the first two modes supported by this structure and identify the cutoff frequencies. b) For each mode identified in a), find the phase constant within the dielectric in the direction normal to the interface when the incident angle (defined via the normal to the interface - as shown below) is twice the critical angle.