A Miniaturized Microstrip Balun Constructed With Two lambda/8 Coupled Lines and a Redundant Line

作者：Shie Ching Ian^*; Pan Yu Han; Chin Kuo Sheng; Chiang Yi Chyun

来源：IEEE Microwave and Wireless Components Letters, 2010, 20(12): 663-665.

DOI：10.1109/LMWC.2010.2084076

• Microstrip balun
• re-entrant coupler
• redundant line

This work presents a miniaturized balun consisting of two re-entrant coupled line sections with similar to lambda/8 length connected by a redundant line with similar to 0.04 lambda length fabricated by planar PCB technology. The structure of the balun was analyzed to obtain the appropriate lengths of couplers and redundant line for the balun realization. An experimental balun operated at S-band was designed and fabricated to verify the proposed structure of balun. The prototype demonstrates a miniaturized dimension of similar to 0.29 lambda x 0.05 lambda and less than 0.36 dB amplitude imbalance associated with 1.6 degrees phase difference in the frequency range of 2.09 similar to 3.06 GHz (37.7%). The return loss in the operation band is less than -10 dB. The length of the prototype is almost shrunk to nearly half of the traditional balun.

• 出版日期2010-12
• 单位长春大学; 中国科学院电工研究所