An L-band HTS duplexer with improved performance  

作　　者：Jia Wang Qiang Zhang Bin Cui Jin Guo YongBo Bian XiaoFeng He ChunGuang Li XueQiang Zhang Hong Li WuXia Li et al. 

机构地区：[1]Chinese Acad Sci, Inst Phys, Beijing 100190, Peoples R China

出　　处：《Chinese Science Bulletin》2010年第31期3527-3532,共6页

基　　金：supported by the External Cooperation Program of the Chinese Academy of Sciences (GJHZ1007);Knowledge Innovation Program of the Chinese Academy of Sciences (KJCX2-YW-W16)

摘　　要：An L-band HTS duplexer with improved performance for communication applications has been developed.This is an improved version of the duplexer previously developed by our group.The duplexer was composed of a T-junction and two channels.Each channel has a 10-pole quasi-elliptic function bandpass HTS filter with a bandwidth of 27 MHz,and center frequencies at 1200 MHz and 1260 MHz.To achieve higher performance,especially a good balance between selectivity and flat group delay,the two pairs of transmission zeros from the two filters were reassigned so that one pair is used for high selectivity and the other for flat group delay.To reduce the influence of parasitical coupling,new coupling structures were developed in the simulation process.The duplexer was fabricated on a 2 inch diameter,0.5 mm thick LaAlO3 wafer with a double-sided YBCO film.The measured results showed a very high performance:a mid-band insertion loss of 0.2 dB,a return loss better than-14 dB,a shape factor better than 1.4:1,an out-of-band rejection of better than 70 dB in a wide frequency range up to 3 GHz and excellent isolation(higher than 80 dB) between the two channels.In addition,the frequency band 5 ns group delay variation is over 10.5 MHz(38.7% of 1 dB bandwidth).An L-band HTS duplexer with improved performance for communication applications has been developed. This is an improved version of the duplexer previously developed by our group. The duplexer was composed of a T-junction and two channels. Each channel has a 10-pole quasi-elliptic function bandpass HTS filter with a bandwidth of 27 MHz, and center frequencies at 1200 MHz and 1260 MHz. To achieve higher performance, especially a good balance between selectivity and flat group delay, the two pairs of transmission zeros from the two filters were reassigned so that one pair is used for high selectivity and the other for flat group delay. To reduce the influence of parasitical coupling, new coupling structures were developed in the simulation process. The duplexer was fabricated on a 2 inch diameter, 0.5 mm thick LaA103 wafer with a double-sided YBCO film. The measured results showed a very high performance： a mid-band insertion loss of 0.2 dB, a return loss better than -14 dB, a shape factor better than 1.4： 1, an out-of-band rejection of better than 70 dB in a wide frequency range up to 3 GHz and excellent isolation （higher than 80 dB） between the two channels. In addition, the frequency band 5 ns group delay variation is over 10.5 MHz （38.7% of 1 dB bandwidth）.

关 键 词：双面打印 高温超导 L波段 性能 带宽滤波器 插入损耗 通信应用 丁字路口 

分 类 号：TN722[电子电信—电路与系统] TP334.84[自动化与计算机技术—计算机系统结构]