摘要
Abstract
Due to the advantages of SAW coupled resonators, such as the large bandwidth with flat passband, low insertion loss, high frequency and small size etc, along with the development of communication tending to higher working frequency and smaller size of equipment, SAW longitudinally coupled resonators and waveguide coupled resonators are widely applied in the communication systems. COM(Coupling-of-modes) theory is one of successful methods for modeling and designing the coupled resonators. The substrate's COM parameters are the basic parameters in COM equations, however so far there are only a few substrates whose COM parameters could be found in the literatures, which prevents the application of COM theory to more substrates.
This paper discusses the COM equations and theoretical formula of COM parameters based on reference, them presents the COM parameters of several commonly used substrates, such as 128°LiNbO, 41°LiNbO, 112°LiTaO and 34°ST Quartz etc. As examples, this paper designed a two-port resonator and a longitudinal coupled duplexer with 1, 3 modes using these parameters; the theoretical results show well agreement with the experimental results. Once we have got more different substrates' COM parameters, we could design and calculate the coupled resonators on more substrates in the future.关键词
耦合谐振器/COM理论/失谐系数/反射系数Key words
coupled resonators/COM theory/detuning parameter/reflection parameter分类
数理科学
