4. Areas of application –

Since the development of microwave-quality substrates and the advent of CAD software that includes open line modeling, more and more microwave circuit designs have been using planar transmission lines. Although the modes carried by these structures are more complex than those carried by homogeneous waveguide structures, they offer clear advantages in terms of:

• bulk and weight;

• ease of implementation in the case of engraved lines;

• miniaturization;

• the ease of insertion of active components;

• of the cost when it comes to large-scale production.