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(a) A Gunn diode is operating in the negative resistance domain at 9.05 GHz inside a WR90 (a = 22.86 mm, b = 10.16 mm) waveguide system. A dielectric cell containing transformer oil with relative permittivity 2.55, is added to the system. Determine (i) The cutoff frequency for the dominant mode fe for an air dielectric within the waveguide. [1] (ii) The cutoff wavelength Ac, for an air dielectric within the waveguide. [1] (iii) The impedance of the dominant mode for an air dielectric within waveguide. [1] (iv) The phase velocity of the dominant mode for an air dielectric. [1] (v) The guide wavelength in the waveguide for an air dielectric. [1] The impedance of the dominant mode for oil filled waveguide cell. [1] (vii) The reflection coefficient at the air/oil dielectric. [1] (viii) The SWR. [1] air filled waveguide oil filled waveguide €€