This paper presents a design method of a balanced-to-unbalanced bandpass filter by using multilayer configuration provided by LTCC (Low Temperature Co-fired Ceramic) tech-nology. The design method for the balun is based on three quarter-wave-length transmission lines. By using the high-frequency simulation software, a balun bandpass filter with two transmission zeros is designed, whose center frequency is 2.45 GHz. Its insertion loss is less than 3.5 dB and size is 2.0 mm × 1.25 mm × 0.9 mm, which is widely used for wireless communication systems. It has smaller size than the balun filter manufactured on PCB (Printed Circuit Board).