Balanced-unbalanced transformation device and method for manufacturing balanced-unbalanced transformation device

摘要

A balanced-unbalanced transformation device includes a plate-like dielectric substrate having a ground electrode and a plurality of major surface electrodes formed thereon. Two of the major surface electrodes are connected to the ground electrode via short-circuit side surface electrodes so as to form ¼ wavelength resonator transmission lines. A third major surface electrode is disposed between the two major surface electrodes and has either end open so as to form a ½ wavelength resonator transmission line. A balancing characteristic adjustment side surface electrode is provided on a side surface of the dielectric substrate. By adjusting a capacitance formed between the balancing characteristic adjustment side surface electrode and the third major surface electrode, a phase balance between two balanced signals is set to a desired value.