We would like to design a single$-$section $10\mathrm{.}8814$ dB coupler for a system impedance of $50,$ and a center frequency of F MHz$.$ The coupler will be designed as a stripline circuit. The substrate of the circuit is b$=2$ mm thick and it has a dielectric constant of $1\mathrm{.}8.$ a$)$ Find the even$-$ and odd$-$mode characteristic impedances. b$)$ Find width and spacing of the coupled lines in mm$.$ c$)$ Find the length of the coupler in mm$.$