This work analyzes antenna coupling effects in small wireless handheld and mobile devices. Further it provides suggestions how to minimize them. Modern communication devices have to support several standards, while the total system and PCB size needs to be decreased. This results in rising mutual coupling. Demands for improved receiver sensitivity and limited transmit power aggravate the requirements on separation of the systems. Part 1 presents information about standards, wave propagation on PCBs, fundamentals of 3D electromagnetic FEM simulations and S-parameter measurement basics. Part 2...