A ______ consists of a central thin conducting strip of width ω which is greater than its thickness t. It is placed inside the low loss dielectric (ϵr) substrate of thickness b/2 between two wide ground plates. The width of the ground plates is five time greater than the spacing between the plates. These are the planar transmission lines, used frequencies from 100MHz to 100GHz.

• A. micro strip line
• B. slot line
• C. parallel strip line
• D. strip line