Numerical investigation of vertical contactless transitions for multilayer RF circuits

This paper presents some concepts for contactless transitions between different planar transmission lines. These types of transitions are important for use in e.g. multilayer designs. Another important reason to avoid galvanic connections at RF is that they may generate passive intermodulation products (PIM), which can be a serious problem in multifrequency systems. The investigated transitions operate in the extended GSM 900 band (880-960 MHz).