小型LTCC巴伦的设计

Design of a miniaturized LTCC balun

提出了一种基于Marchand巴伦结构的小型化半集总参数巴伦。通过加载端电容和谐振电容减小巴伦耦合线电长度，LTCC多层布线的实现方式进一步减小了巴伦的实际体积。采用奇偶模分析方法对该结构进行分析，给出了设计曲线，采用A6-M材料仿真并制作出尺寸为2．5mm×2．0mm×1．0mm的巴伦。测得在2．7～2．9GHz，S11小于-15dB，幅度不平衡度小于±0．5dB，相位不平衡度小于±10°。最后分析了仿真值和实测值的差异的原因。

A miniaturized semi-lumped balun based on Marchand balun was proposed. Loading terminal capacitors and resonant capacitors were employed in this structure to reduce the electric length of the coupling line. The size of the balun was further reduced due to the multilayer structure based on LTCC technology. The proposed structure was analyzed in detail using even-odd mode analysis method and some design curves were achieved. The balun with the size of 2.5 mm×2.0 mm×l.0 mm was simulated and fabricated by using the A6-M material. The results show that parameters of the fabricated balun are the amplitude imbalance of=±0.5 dB and the phase imbalance of±10°, with over the S11 of-15 dB in 2.7-2.9 GHz. The reason for variance between the simulation value and the test value was analyzed.