The development of modern communication systems is challenged by increasing demands on overall performance and decreasing turn-around times. Therefore, a fast and reliable component design process is at the center of a timely system prototyping concept. This thesis focuses on developing design methodologies for passive microwave components. They are derived from the coupling between various parts of a microwave circuit and take into account the physics of electromagnetic interactions between elements.

A generalized coupling theory is presented which can consider the effects of external fields on the coupling between circuit structures. Different circuit technologies are combined to achieve a microstrip-stripline coupler design with power handling capabilities and small components size. A slot coupler design methodology is presented which uses field averaging concepts to account for coupling through large apertures. A relatively small yet high power waveguide rotary joint design is presented for X-band radar systems. An innovative topology and design concept is demonstrated for filters fabricated in LTCC technology. A theoretical model for signal tapping pads is developed and applied to a novel low pass filter design including capacitive pads and lumped inductors. A broadband equivalent circuit model for electromagnetic band gap structures is presented and its application for a printed circuit GPS antenna is illustrated.

The initial design techniques, methodologies and strategies developed in this thesis are validated by comparison with measurements or other independently obtained results, e.g., from commercially available software packages.