Printed circuit board built-in type planar balun and method for manufacturing same

摘要

A printed circuit board built-in type planar balun which can be easily incorporated in a printed circuit board without increasing the number of layers and lowering the functions thereof is provided. A balanced signal transmission line 1 and an unbalanced signal transmission line 2 are formed on a same plane, with the sides being opposed to each other. Dielectric layers 3 are provided between these transmission lines, and between the transmission line and a ground potential layer 4 which is arranged substantially parallel to the lines 1 and 2 and spaced at a predetermined distance.