A physical description of soft and hard surfaces and how to use them

A simple physical description of how soft and hard surfaces work for waves propagating along them is presented. Wave propagation along a plane conductor is considered. Then, conductor is coated with a dielectric layer, and the dielectric layer is loaded with strips to become soft or hard. Important areas of future research are indicated. Two examples of how the thought model of soft and hard surfaces can be used constructively to find new solutions to important antenna problems are given.<>