Design of three-dimensional balun based on LTCC technology

摘要

Balun, which means balanced-to-unbalanced transformer, is widely used in wireless communication systems. Balun can transform an unbalanced input signal into balanced output having equal magnitudes, 180° phase shift and vice-versa. As miniaturization is an inevitable trend of the development of today's electronic devices, the study of the miniaturization of balun is of great significance. To realize the miniaturization of balun, a three-dimensional structure to design based on LTCC technology is used in our design. The frequency range of this balun is 1.1–2.5GHz, the amplitude unbalance is lower than 0.4dB, and the phase unbalance is smaller than 4 degree. The advantage of this design is of its small size and nice balance feature.